INSTRUCTION
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Check whether an array-like is a periodical array-like or PeriodIndex.
Parameters
----------
arr : array-like
The array-like to check.
Returns
-------
boolean
Whether or not the array-like is a periodical array-like or
PeriodIndex instance.
Examples
--------
>>> is_period_arraylike([1, 2, 3])
False
>>> is_period_arraylike(pd.Index([1, 2, 3]))
False
>>> is_period_arraylike(pd.PeriodIndex(["2017-01-01"], freq="D"))
True | def is_period_arraylike(arr):
"""
Check whether an array-like is a periodical array-like or PeriodIndex.
Parameters
----------
arr : array-like
The array-like to check.
Returns
-------
boolean
Whether or not the array-like is a periodical array-like or
PeriodIndex instance.
Examples
--------
>>> is_period_arraylike([1, 2, 3])
False
>>> is_period_arraylike(pd.Index([1, 2, 3]))
False
>>> is_period_arraylike(pd.PeriodIndex(["2017-01-01"], freq="D"))
True
"""
if isinstance(arr, (ABCPeriodIndex, ABCPeriodArray)):
return True
elif isinstance(arr, (np.ndarray, ABCSeries)):
return is_period_dtype(arr.dtype)
return getattr(arr, 'inferred_type', None) == 'period' |
Check whether an array-like is a datetime array-like or DatetimeIndex.
Parameters
----------
arr : array-like
The array-like to check.
Returns
-------
boolean
Whether or not the array-like is a datetime array-like or
DatetimeIndex.
Examples
--------
>>> is_datetime_arraylike([1, 2, 3])
False
>>> is_datetime_arraylike(pd.Index([1, 2, 3]))
False
>>> is_datetime_arraylike(pd.DatetimeIndex([1, 2, 3]))
True | def is_datetime_arraylike(arr):
"""
Check whether an array-like is a datetime array-like or DatetimeIndex.
Parameters
----------
arr : array-like
The array-like to check.
Returns
-------
boolean
Whether or not the array-like is a datetime array-like or
DatetimeIndex.
Examples
--------
>>> is_datetime_arraylike([1, 2, 3])
False
>>> is_datetime_arraylike(pd.Index([1, 2, 3]))
False
>>> is_datetime_arraylike(pd.DatetimeIndex([1, 2, 3]))
True
"""
if isinstance(arr, ABCDatetimeIndex):
return True
elif isinstance(arr, (np.ndarray, ABCSeries)):
return (is_object_dtype(arr.dtype)
and lib.infer_dtype(arr, skipna=False) == 'datetime')
return getattr(arr, 'inferred_type', None) == 'datetime' |
Check whether an array-like is a datetime-like array-like.
Acceptable datetime-like objects are (but not limited to) datetime
indices, periodic indices, and timedelta indices.
Parameters
----------
arr : array-like
The array-like to check.
Returns
-------
boolean
Whether or not the array-like is a datetime-like array-like.
Examples
--------
>>> is_datetimelike([1, 2, 3])
False
>>> is_datetimelike(pd.Index([1, 2, 3]))
False
>>> is_datetimelike(pd.DatetimeIndex([1, 2, 3]))
True
>>> is_datetimelike(pd.DatetimeIndex([1, 2, 3], tz="US/Eastern"))
True
>>> is_datetimelike(pd.PeriodIndex([], freq="A"))
True
>>> is_datetimelike(np.array([], dtype=np.datetime64))
True
>>> is_datetimelike(pd.Series([], dtype="timedelta64[ns]"))
True
>>>
>>> dtype = DatetimeTZDtype("ns", tz="US/Eastern")
>>> s = pd.Series([], dtype=dtype)
>>> is_datetimelike(s)
True | def is_datetimelike(arr):
"""
Check whether an array-like is a datetime-like array-like.
Acceptable datetime-like objects are (but not limited to) datetime
indices, periodic indices, and timedelta indices.
Parameters
----------
arr : array-like
The array-like to check.
Returns
-------
boolean
Whether or not the array-like is a datetime-like array-like.
Examples
--------
>>> is_datetimelike([1, 2, 3])
False
>>> is_datetimelike(pd.Index([1, 2, 3]))
False
>>> is_datetimelike(pd.DatetimeIndex([1, 2, 3]))
True
>>> is_datetimelike(pd.DatetimeIndex([1, 2, 3], tz="US/Eastern"))
True
>>> is_datetimelike(pd.PeriodIndex([], freq="A"))
True
>>> is_datetimelike(np.array([], dtype=np.datetime64))
True
>>> is_datetimelike(pd.Series([], dtype="timedelta64[ns]"))
True
>>>
>>> dtype = DatetimeTZDtype("ns", tz="US/Eastern")
>>> s = pd.Series([], dtype=dtype)
>>> is_datetimelike(s)
True
"""
return (is_datetime64_dtype(arr) or is_datetime64tz_dtype(arr) or
is_timedelta64_dtype(arr) or
isinstance(arr, ABCPeriodIndex)) |
Check if two dtypes are equal.
Parameters
----------
source : The first dtype to compare
target : The second dtype to compare
Returns
----------
boolean
Whether or not the two dtypes are equal.
Examples
--------
>>> is_dtype_equal(int, float)
False
>>> is_dtype_equal("int", int)
True
>>> is_dtype_equal(object, "category")
False
>>> is_dtype_equal(CategoricalDtype(), "category")
True
>>> is_dtype_equal(DatetimeTZDtype(), "datetime64")
False | def is_dtype_equal(source, target):
"""
Check if two dtypes are equal.
Parameters
----------
source : The first dtype to compare
target : The second dtype to compare
Returns
----------
boolean
Whether or not the two dtypes are equal.
Examples
--------
>>> is_dtype_equal(int, float)
False
>>> is_dtype_equal("int", int)
True
>>> is_dtype_equal(object, "category")
False
>>> is_dtype_equal(CategoricalDtype(), "category")
True
>>> is_dtype_equal(DatetimeTZDtype(), "datetime64")
False
"""
try:
source = _get_dtype(source)
target = _get_dtype(target)
return source == target
except (TypeError, AttributeError):
# invalid comparison
# object == category will hit this
return False |
Check whether two arrays have compatible dtypes to do a union.
numpy types are checked with ``is_dtype_equal``. Extension types are
checked separately.
Parameters
----------
source : The first dtype to compare
target : The second dtype to compare
Returns
----------
boolean
Whether or not the two dtypes are equal.
>>> is_dtype_equal("int", int)
True
>>> is_dtype_equal(CategoricalDtype(['a', 'b'],
... CategoricalDtype(['b', 'c']))
True
>>> is_dtype_equal(CategoricalDtype(['a', 'b'],
... CategoricalDtype(['b', 'c'], ordered=True))
False | def is_dtype_union_equal(source, target):
"""
Check whether two arrays have compatible dtypes to do a union.
numpy types are checked with ``is_dtype_equal``. Extension types are
checked separately.
Parameters
----------
source : The first dtype to compare
target : The second dtype to compare
Returns
----------
boolean
Whether or not the two dtypes are equal.
>>> is_dtype_equal("int", int)
True
>>> is_dtype_equal(CategoricalDtype(['a', 'b'],
... CategoricalDtype(['b', 'c']))
True
>>> is_dtype_equal(CategoricalDtype(['a', 'b'],
... CategoricalDtype(['b', 'c'], ordered=True))
False
"""
source = _get_dtype(source)
target = _get_dtype(target)
if is_categorical_dtype(source) and is_categorical_dtype(target):
# ordered False for both
return source.ordered is target.ordered
return is_dtype_equal(source, target) |
Check whether the provided array or dtype is of the datetime64[ns] dtype.
Parameters
----------
arr_or_dtype : array-like
The array or dtype to check.
Returns
-------
boolean
Whether or not the array or dtype is of the datetime64[ns] dtype.
Examples
--------
>>> is_datetime64_ns_dtype(str)
False
>>> is_datetime64_ns_dtype(int)
False
>>> is_datetime64_ns_dtype(np.datetime64) # no unit
False
>>> is_datetime64_ns_dtype(DatetimeTZDtype("ns", "US/Eastern"))
True
>>> is_datetime64_ns_dtype(np.array(['a', 'b']))
False
>>> is_datetime64_ns_dtype(np.array([1, 2]))
False
>>> is_datetime64_ns_dtype(np.array([], dtype=np.datetime64)) # no unit
False
>>> is_datetime64_ns_dtype(np.array([],
dtype="datetime64[ps]")) # wrong unit
False
>>> is_datetime64_ns_dtype(pd.DatetimeIndex([1, 2, 3],
dtype=np.datetime64)) # has 'ns' unit
True | def is_datetime64_ns_dtype(arr_or_dtype):
"""
Check whether the provided array or dtype is of the datetime64[ns] dtype.
Parameters
----------
arr_or_dtype : array-like
The array or dtype to check.
Returns
-------
boolean
Whether or not the array or dtype is of the datetime64[ns] dtype.
Examples
--------
>>> is_datetime64_ns_dtype(str)
False
>>> is_datetime64_ns_dtype(int)
False
>>> is_datetime64_ns_dtype(np.datetime64) # no unit
False
>>> is_datetime64_ns_dtype(DatetimeTZDtype("ns", "US/Eastern"))
True
>>> is_datetime64_ns_dtype(np.array(['a', 'b']))
False
>>> is_datetime64_ns_dtype(np.array([1, 2]))
False
>>> is_datetime64_ns_dtype(np.array([], dtype=np.datetime64)) # no unit
False
>>> is_datetime64_ns_dtype(np.array([],
dtype="datetime64[ps]")) # wrong unit
False
>>> is_datetime64_ns_dtype(pd.DatetimeIndex([1, 2, 3],
dtype=np.datetime64)) # has 'ns' unit
True
"""
if arr_or_dtype is None:
return False
try:
tipo = _get_dtype(arr_or_dtype)
except TypeError:
if is_datetime64tz_dtype(arr_or_dtype):
tipo = _get_dtype(arr_or_dtype.dtype)
else:
return False
return tipo == _NS_DTYPE or getattr(tipo, 'base', None) == _NS_DTYPE |
Check if we are comparing a string-like object to a numeric ndarray.
NumPy doesn't like to compare such objects, especially numeric arrays
and scalar string-likes.
Parameters
----------
a : array-like, scalar
The first object to check.
b : array-like, scalar
The second object to check.
Returns
-------
boolean
Whether we return a comparing a string-like object to a numeric array.
Examples
--------
>>> is_numeric_v_string_like(1, 1)
False
>>> is_numeric_v_string_like("foo", "foo")
False
>>> is_numeric_v_string_like(1, "foo") # non-array numeric
False
>>> is_numeric_v_string_like(np.array([1]), "foo")
True
>>> is_numeric_v_string_like("foo", np.array([1])) # symmetric check
True
>>> is_numeric_v_string_like(np.array([1, 2]), np.array(["foo"]))
True
>>> is_numeric_v_string_like(np.array(["foo"]), np.array([1, 2]))
True
>>> is_numeric_v_string_like(np.array([1]), np.array([2]))
False
>>> is_numeric_v_string_like(np.array(["foo"]), np.array(["foo"]))
False | def is_numeric_v_string_like(a, b):
"""
Check if we are comparing a string-like object to a numeric ndarray.
NumPy doesn't like to compare such objects, especially numeric arrays
and scalar string-likes.
Parameters
----------
a : array-like, scalar
The first object to check.
b : array-like, scalar
The second object to check.
Returns
-------
boolean
Whether we return a comparing a string-like object to a numeric array.
Examples
--------
>>> is_numeric_v_string_like(1, 1)
False
>>> is_numeric_v_string_like("foo", "foo")
False
>>> is_numeric_v_string_like(1, "foo") # non-array numeric
False
>>> is_numeric_v_string_like(np.array([1]), "foo")
True
>>> is_numeric_v_string_like("foo", np.array([1])) # symmetric check
True
>>> is_numeric_v_string_like(np.array([1, 2]), np.array(["foo"]))
True
>>> is_numeric_v_string_like(np.array(["foo"]), np.array([1, 2]))
True
>>> is_numeric_v_string_like(np.array([1]), np.array([2]))
False
>>> is_numeric_v_string_like(np.array(["foo"]), np.array(["foo"]))
False
"""
is_a_array = isinstance(a, np.ndarray)
is_b_array = isinstance(b, np.ndarray)
is_a_numeric_array = is_a_array and is_numeric_dtype(a)
is_b_numeric_array = is_b_array and is_numeric_dtype(b)
is_a_string_array = is_a_array and is_string_like_dtype(a)
is_b_string_array = is_b_array and is_string_like_dtype(b)
is_a_scalar_string_like = not is_a_array and is_string_like(a)
is_b_scalar_string_like = not is_b_array and is_string_like(b)
return ((is_a_numeric_array and is_b_scalar_string_like) or
(is_b_numeric_array and is_a_scalar_string_like) or
(is_a_numeric_array and is_b_string_array) or
(is_b_numeric_array and is_a_string_array)) |
Check if we are comparing a datetime-like object to a numeric object.
By "numeric," we mean an object that is either of an int or float dtype.
Parameters
----------
a : array-like, scalar
The first object to check.
b : array-like, scalar
The second object to check.
Returns
-------
boolean
Whether we return a comparing a datetime-like to a numeric object.
Examples
--------
>>> dt = np.datetime64(pd.datetime(2017, 1, 1))
>>>
>>> is_datetimelike_v_numeric(1, 1)
False
>>> is_datetimelike_v_numeric(dt, dt)
False
>>> is_datetimelike_v_numeric(1, dt)
True
>>> is_datetimelike_v_numeric(dt, 1) # symmetric check
True
>>> is_datetimelike_v_numeric(np.array([dt]), 1)
True
>>> is_datetimelike_v_numeric(np.array([1]), dt)
True
>>> is_datetimelike_v_numeric(np.array([dt]), np.array([1]))
True
>>> is_datetimelike_v_numeric(np.array([1]), np.array([2]))
False
>>> is_datetimelike_v_numeric(np.array([dt]), np.array([dt]))
False | def is_datetimelike_v_numeric(a, b):
"""
Check if we are comparing a datetime-like object to a numeric object.
By "numeric," we mean an object that is either of an int or float dtype.
Parameters
----------
a : array-like, scalar
The first object to check.
b : array-like, scalar
The second object to check.
Returns
-------
boolean
Whether we return a comparing a datetime-like to a numeric object.
Examples
--------
>>> dt = np.datetime64(pd.datetime(2017, 1, 1))
>>>
>>> is_datetimelike_v_numeric(1, 1)
False
>>> is_datetimelike_v_numeric(dt, dt)
False
>>> is_datetimelike_v_numeric(1, dt)
True
>>> is_datetimelike_v_numeric(dt, 1) # symmetric check
True
>>> is_datetimelike_v_numeric(np.array([dt]), 1)
True
>>> is_datetimelike_v_numeric(np.array([1]), dt)
True
>>> is_datetimelike_v_numeric(np.array([dt]), np.array([1]))
True
>>> is_datetimelike_v_numeric(np.array([1]), np.array([2]))
False
>>> is_datetimelike_v_numeric(np.array([dt]), np.array([dt]))
False
"""
if not hasattr(a, 'dtype'):
a = np.asarray(a)
if not hasattr(b, 'dtype'):
b = np.asarray(b)
def is_numeric(x):
"""
Check if an object has a numeric dtype (i.e. integer or float).
"""
return is_integer_dtype(x) or is_float_dtype(x)
is_datetimelike = needs_i8_conversion
return ((is_datetimelike(a) and is_numeric(b)) or
(is_datetimelike(b) and is_numeric(a))) |
Check if we are comparing a datetime-like object to an object instance.
Parameters
----------
a : array-like, scalar
The first object to check.
b : array-like, scalar
The second object to check.
Returns
-------
boolean
Whether we return a comparing a datetime-like to an object instance.
Examples
--------
>>> obj = object()
>>> dt = np.datetime64(pd.datetime(2017, 1, 1))
>>>
>>> is_datetimelike_v_object(obj, obj)
False
>>> is_datetimelike_v_object(dt, dt)
False
>>> is_datetimelike_v_object(obj, dt)
True
>>> is_datetimelike_v_object(dt, obj) # symmetric check
True
>>> is_datetimelike_v_object(np.array([dt]), obj)
True
>>> is_datetimelike_v_object(np.array([obj]), dt)
True
>>> is_datetimelike_v_object(np.array([dt]), np.array([obj]))
True
>>> is_datetimelike_v_object(np.array([obj]), np.array([obj]))
False
>>> is_datetimelike_v_object(np.array([dt]), np.array([1]))
False
>>> is_datetimelike_v_object(np.array([dt]), np.array([dt]))
False | def is_datetimelike_v_object(a, b):
"""
Check if we are comparing a datetime-like object to an object instance.
Parameters
----------
a : array-like, scalar
The first object to check.
b : array-like, scalar
The second object to check.
Returns
-------
boolean
Whether we return a comparing a datetime-like to an object instance.
Examples
--------
>>> obj = object()
>>> dt = np.datetime64(pd.datetime(2017, 1, 1))
>>>
>>> is_datetimelike_v_object(obj, obj)
False
>>> is_datetimelike_v_object(dt, dt)
False
>>> is_datetimelike_v_object(obj, dt)
True
>>> is_datetimelike_v_object(dt, obj) # symmetric check
True
>>> is_datetimelike_v_object(np.array([dt]), obj)
True
>>> is_datetimelike_v_object(np.array([obj]), dt)
True
>>> is_datetimelike_v_object(np.array([dt]), np.array([obj]))
True
>>> is_datetimelike_v_object(np.array([obj]), np.array([obj]))
False
>>> is_datetimelike_v_object(np.array([dt]), np.array([1]))
False
>>> is_datetimelike_v_object(np.array([dt]), np.array([dt]))
False
"""
if not hasattr(a, 'dtype'):
a = np.asarray(a)
if not hasattr(b, 'dtype'):
b = np.asarray(b)
is_datetimelike = needs_i8_conversion
return ((is_datetimelike(a) and is_object_dtype(b)) or
(is_datetimelike(b) and is_object_dtype(a))) |
Check whether the array or dtype should be converted to int64.
An array-like or dtype "needs" such a conversion if the array-like
or dtype is of a datetime-like dtype
Parameters
----------
arr_or_dtype : array-like
The array or dtype to check.
Returns
-------
boolean
Whether or not the array or dtype should be converted to int64.
Examples
--------
>>> needs_i8_conversion(str)
False
>>> needs_i8_conversion(np.int64)
False
>>> needs_i8_conversion(np.datetime64)
True
>>> needs_i8_conversion(np.array(['a', 'b']))
False
>>> needs_i8_conversion(pd.Series([1, 2]))
False
>>> needs_i8_conversion(pd.Series([], dtype="timedelta64[ns]"))
True
>>> needs_i8_conversion(pd.DatetimeIndex([1, 2, 3], tz="US/Eastern"))
True | def needs_i8_conversion(arr_or_dtype):
"""
Check whether the array or dtype should be converted to int64.
An array-like or dtype "needs" such a conversion if the array-like
or dtype is of a datetime-like dtype
Parameters
----------
arr_or_dtype : array-like
The array or dtype to check.
Returns
-------
boolean
Whether or not the array or dtype should be converted to int64.
Examples
--------
>>> needs_i8_conversion(str)
False
>>> needs_i8_conversion(np.int64)
False
>>> needs_i8_conversion(np.datetime64)
True
>>> needs_i8_conversion(np.array(['a', 'b']))
False
>>> needs_i8_conversion(pd.Series([1, 2]))
False
>>> needs_i8_conversion(pd.Series([], dtype="timedelta64[ns]"))
True
>>> needs_i8_conversion(pd.DatetimeIndex([1, 2, 3], tz="US/Eastern"))
True
"""
if arr_or_dtype is None:
return False
return (is_datetime_or_timedelta_dtype(arr_or_dtype) or
is_datetime64tz_dtype(arr_or_dtype) or
is_period_dtype(arr_or_dtype)) |
Check whether the provided array or dtype is of a boolean dtype.
Parameters
----------
arr_or_dtype : array-like
The array or dtype to check.
Returns
-------
boolean
Whether or not the array or dtype is of a boolean dtype.
Notes
-----
An ExtensionArray is considered boolean when the ``_is_boolean``
attribute is set to True.
Examples
--------
>>> is_bool_dtype(str)
False
>>> is_bool_dtype(int)
False
>>> is_bool_dtype(bool)
True
>>> is_bool_dtype(np.bool)
True
>>> is_bool_dtype(np.array(['a', 'b']))
False
>>> is_bool_dtype(pd.Series([1, 2]))
False
>>> is_bool_dtype(np.array([True, False]))
True
>>> is_bool_dtype(pd.Categorical([True, False]))
True
>>> is_bool_dtype(pd.SparseArray([True, False]))
True | def is_bool_dtype(arr_or_dtype):
"""
Check whether the provided array or dtype is of a boolean dtype.
Parameters
----------
arr_or_dtype : array-like
The array or dtype to check.
Returns
-------
boolean
Whether or not the array or dtype is of a boolean dtype.
Notes
-----
An ExtensionArray is considered boolean when the ``_is_boolean``
attribute is set to True.
Examples
--------
>>> is_bool_dtype(str)
False
>>> is_bool_dtype(int)
False
>>> is_bool_dtype(bool)
True
>>> is_bool_dtype(np.bool)
True
>>> is_bool_dtype(np.array(['a', 'b']))
False
>>> is_bool_dtype(pd.Series([1, 2]))
False
>>> is_bool_dtype(np.array([True, False]))
True
>>> is_bool_dtype(pd.Categorical([True, False]))
True
>>> is_bool_dtype(pd.SparseArray([True, False]))
True
"""
if arr_or_dtype is None:
return False
try:
dtype = _get_dtype(arr_or_dtype)
except TypeError:
return False
if isinstance(arr_or_dtype, CategoricalDtype):
arr_or_dtype = arr_or_dtype.categories
# now we use the special definition for Index
if isinstance(arr_or_dtype, ABCIndexClass):
# TODO(jreback)
# we don't have a boolean Index class
# so its object, we need to infer to
# guess this
return (arr_or_dtype.is_object and
arr_or_dtype.inferred_type == 'boolean')
elif is_extension_array_dtype(arr_or_dtype):
dtype = getattr(arr_or_dtype, 'dtype', arr_or_dtype)
return dtype._is_boolean
return issubclass(dtype.type, np.bool_) |
Check whether an array-like is of a pandas extension class instance.
Extension classes include categoricals, pandas sparse objects (i.e.
classes represented within the pandas library and not ones external
to it like scipy sparse matrices), and datetime-like arrays.
Parameters
----------
arr : array-like
The array-like to check.
Returns
-------
boolean
Whether or not the array-like is of a pandas extension class instance.
Examples
--------
>>> is_extension_type([1, 2, 3])
False
>>> is_extension_type(np.array([1, 2, 3]))
False
>>>
>>> cat = pd.Categorical([1, 2, 3])
>>>
>>> is_extension_type(cat)
True
>>> is_extension_type(pd.Series(cat))
True
>>> is_extension_type(pd.SparseArray([1, 2, 3]))
True
>>> is_extension_type(pd.SparseSeries([1, 2, 3]))
True
>>>
>>> from scipy.sparse import bsr_matrix
>>> is_extension_type(bsr_matrix([1, 2, 3]))
False
>>> is_extension_type(pd.DatetimeIndex([1, 2, 3]))
False
>>> is_extension_type(pd.DatetimeIndex([1, 2, 3], tz="US/Eastern"))
True
>>>
>>> dtype = DatetimeTZDtype("ns", tz="US/Eastern")
>>> s = pd.Series([], dtype=dtype)
>>> is_extension_type(s)
True | def is_extension_type(arr):
"""
Check whether an array-like is of a pandas extension class instance.
Extension classes include categoricals, pandas sparse objects (i.e.
classes represented within the pandas library and not ones external
to it like scipy sparse matrices), and datetime-like arrays.
Parameters
----------
arr : array-like
The array-like to check.
Returns
-------
boolean
Whether or not the array-like is of a pandas extension class instance.
Examples
--------
>>> is_extension_type([1, 2, 3])
False
>>> is_extension_type(np.array([1, 2, 3]))
False
>>>
>>> cat = pd.Categorical([1, 2, 3])
>>>
>>> is_extension_type(cat)
True
>>> is_extension_type(pd.Series(cat))
True
>>> is_extension_type(pd.SparseArray([1, 2, 3]))
True
>>> is_extension_type(pd.SparseSeries([1, 2, 3]))
True
>>>
>>> from scipy.sparse import bsr_matrix
>>> is_extension_type(bsr_matrix([1, 2, 3]))
False
>>> is_extension_type(pd.DatetimeIndex([1, 2, 3]))
False
>>> is_extension_type(pd.DatetimeIndex([1, 2, 3], tz="US/Eastern"))
True
>>>
>>> dtype = DatetimeTZDtype("ns", tz="US/Eastern")
>>> s = pd.Series([], dtype=dtype)
>>> is_extension_type(s)
True
"""
if is_categorical(arr):
return True
elif is_sparse(arr):
return True
elif is_datetime64tz_dtype(arr):
return True
return False |
Check if an object is a pandas extension array type.
See the :ref:`Use Guide <extending.extension-types>` for more.
Parameters
----------
arr_or_dtype : object
For array-like input, the ``.dtype`` attribute will
be extracted.
Returns
-------
bool
Whether the `arr_or_dtype` is an extension array type.
Notes
-----
This checks whether an object implements the pandas extension
array interface. In pandas, this includes:
* Categorical
* Sparse
* Interval
* Period
* DatetimeArray
* TimedeltaArray
Third-party libraries may implement arrays or types satisfying
this interface as well.
Examples
--------
>>> from pandas.api.types import is_extension_array_dtype
>>> arr = pd.Categorical(['a', 'b'])
>>> is_extension_array_dtype(arr)
True
>>> is_extension_array_dtype(arr.dtype)
True
>>> arr = np.array(['a', 'b'])
>>> is_extension_array_dtype(arr.dtype)
False | def is_extension_array_dtype(arr_or_dtype):
"""
Check if an object is a pandas extension array type.
See the :ref:`Use Guide <extending.extension-types>` for more.
Parameters
----------
arr_or_dtype : object
For array-like input, the ``.dtype`` attribute will
be extracted.
Returns
-------
bool
Whether the `arr_or_dtype` is an extension array type.
Notes
-----
This checks whether an object implements the pandas extension
array interface. In pandas, this includes:
* Categorical
* Sparse
* Interval
* Period
* DatetimeArray
* TimedeltaArray
Third-party libraries may implement arrays or types satisfying
this interface as well.
Examples
--------
>>> from pandas.api.types import is_extension_array_dtype
>>> arr = pd.Categorical(['a', 'b'])
>>> is_extension_array_dtype(arr)
True
>>> is_extension_array_dtype(arr.dtype)
True
>>> arr = np.array(['a', 'b'])
>>> is_extension_array_dtype(arr.dtype)
False
"""
dtype = getattr(arr_or_dtype, 'dtype', arr_or_dtype)
return (isinstance(dtype, ExtensionDtype) or
registry.find(dtype) is not None) |
Return a boolean if the condition is satisfied for the arr_or_dtype.
Parameters
----------
arr_or_dtype : array-like, str, np.dtype, or ExtensionArrayType
The array-like or dtype object whose dtype we want to extract.
condition : callable[Union[np.dtype, ExtensionDtype]]
Returns
-------
bool | def _is_dtype(arr_or_dtype, condition):
"""
Return a boolean if the condition is satisfied for the arr_or_dtype.
Parameters
----------
arr_or_dtype : array-like, str, np.dtype, or ExtensionArrayType
The array-like or dtype object whose dtype we want to extract.
condition : callable[Union[np.dtype, ExtensionDtype]]
Returns
-------
bool
"""
if arr_or_dtype is None:
return False
try:
dtype = _get_dtype(arr_or_dtype)
except (TypeError, ValueError, UnicodeEncodeError):
return False
return condition(dtype) |
Get the dtype instance associated with an array
or dtype object.
Parameters
----------
arr_or_dtype : array-like
The array-like or dtype object whose dtype we want to extract.
Returns
-------
obj_dtype : The extract dtype instance from the
passed in array or dtype object.
Raises
------
TypeError : The passed in object is None. | def _get_dtype(arr_or_dtype):
"""
Get the dtype instance associated with an array
or dtype object.
Parameters
----------
arr_or_dtype : array-like
The array-like or dtype object whose dtype we want to extract.
Returns
-------
obj_dtype : The extract dtype instance from the
passed in array or dtype object.
Raises
------
TypeError : The passed in object is None.
"""
if arr_or_dtype is None:
raise TypeError("Cannot deduce dtype from null object")
# fastpath
elif isinstance(arr_or_dtype, np.dtype):
return arr_or_dtype
elif isinstance(arr_or_dtype, type):
return np.dtype(arr_or_dtype)
# if we have an array-like
elif hasattr(arr_or_dtype, 'dtype'):
arr_or_dtype = arr_or_dtype.dtype
return pandas_dtype(arr_or_dtype) |
Return a boolean if the condition is satisfied for the arr_or_dtype.
Parameters
----------
arr_or_dtype : array-like
The array-like or dtype object whose dtype we want to extract.
condition : callable[Union[np.dtype, ExtensionDtypeType]]
Returns
-------
bool : if the condition is satisifed for the arr_or_dtype | def _is_dtype_type(arr_or_dtype, condition):
"""
Return a boolean if the condition is satisfied for the arr_or_dtype.
Parameters
----------
arr_or_dtype : array-like
The array-like or dtype object whose dtype we want to extract.
condition : callable[Union[np.dtype, ExtensionDtypeType]]
Returns
-------
bool : if the condition is satisifed for the arr_or_dtype
"""
if arr_or_dtype is None:
return condition(type(None))
# fastpath
if isinstance(arr_or_dtype, np.dtype):
return condition(arr_or_dtype.type)
elif isinstance(arr_or_dtype, type):
if issubclass(arr_or_dtype, (PandasExtensionDtype, ExtensionDtype)):
arr_or_dtype = arr_or_dtype.type
return condition(np.dtype(arr_or_dtype).type)
elif arr_or_dtype is None:
return condition(type(None))
# if we have an array-like
if hasattr(arr_or_dtype, 'dtype'):
arr_or_dtype = arr_or_dtype.dtype
# we are not possibly a dtype
elif is_list_like(arr_or_dtype):
return condition(type(None))
try:
tipo = pandas_dtype(arr_or_dtype).type
except (TypeError, ValueError, UnicodeEncodeError):
if is_scalar(arr_or_dtype):
return condition(type(None))
return False
return condition(tipo) |
Get a numpy dtype.type-style object for a dtype object.
This methods also includes handling of the datetime64[ns] and
datetime64[ns, TZ] objects.
If no dtype can be found, we return ``object``.
Parameters
----------
dtype : dtype, type
The dtype object whose numpy dtype.type-style
object we want to extract.
Returns
-------
dtype_object : The extracted numpy dtype.type-style object. | def infer_dtype_from_object(dtype):
"""
Get a numpy dtype.type-style object for a dtype object.
This methods also includes handling of the datetime64[ns] and
datetime64[ns, TZ] objects.
If no dtype can be found, we return ``object``.
Parameters
----------
dtype : dtype, type
The dtype object whose numpy dtype.type-style
object we want to extract.
Returns
-------
dtype_object : The extracted numpy dtype.type-style object.
"""
if isinstance(dtype, type) and issubclass(dtype, np.generic):
# Type object from a dtype
return dtype
elif isinstance(dtype, (np.dtype, PandasExtensionDtype, ExtensionDtype)):
# dtype object
try:
_validate_date_like_dtype(dtype)
except TypeError:
# Should still pass if we don't have a date-like
pass
return dtype.type
try:
dtype = pandas_dtype(dtype)
except TypeError:
pass
if is_extension_array_dtype(dtype):
return dtype.type
elif isinstance(dtype, str):
# TODO(jreback)
# should deprecate these
if dtype in ['datetimetz', 'datetime64tz']:
return DatetimeTZDtype.type
elif dtype in ['period']:
raise NotImplementedError
if dtype == 'datetime' or dtype == 'timedelta':
dtype += '64'
try:
return infer_dtype_from_object(getattr(np, dtype))
except (AttributeError, TypeError):
# Handles cases like _get_dtype(int) i.e.,
# Python objects that are valid dtypes
# (unlike user-defined types, in general)
#
# TypeError handles the float16 type code of 'e'
# further handle internal types
pass
return infer_dtype_from_object(np.dtype(dtype)) |
Check whether the dtype is a date-like dtype. Raises an error if invalid.
Parameters
----------
dtype : dtype, type
The dtype to check.
Raises
------
TypeError : The dtype could not be casted to a date-like dtype.
ValueError : The dtype is an illegal date-like dtype (e.g. the
the frequency provided is too specific) | def _validate_date_like_dtype(dtype):
"""
Check whether the dtype is a date-like dtype. Raises an error if invalid.
Parameters
----------
dtype : dtype, type
The dtype to check.
Raises
------
TypeError : The dtype could not be casted to a date-like dtype.
ValueError : The dtype is an illegal date-like dtype (e.g. the
the frequency provided is too specific)
"""
try:
typ = np.datetime_data(dtype)[0]
except ValueError as e:
raise TypeError('{error}'.format(error=e))
if typ != 'generic' and typ != 'ns':
msg = '{name!r} is too specific of a frequency, try passing {type!r}'
raise ValueError(msg.format(name=dtype.name, type=dtype.type.__name__)) |
Convert input into a pandas only dtype object or a numpy dtype object.
Parameters
----------
dtype : object to be converted
Returns
-------
np.dtype or a pandas dtype
Raises
------
TypeError if not a dtype | def pandas_dtype(dtype):
"""
Convert input into a pandas only dtype object or a numpy dtype object.
Parameters
----------
dtype : object to be converted
Returns
-------
np.dtype or a pandas dtype
Raises
------
TypeError if not a dtype
"""
# short-circuit
if isinstance(dtype, np.ndarray):
return dtype.dtype
elif isinstance(dtype, (np.dtype, PandasExtensionDtype, ExtensionDtype)):
return dtype
# registered extension types
result = registry.find(dtype)
if result is not None:
return result
# try a numpy dtype
# raise a consistent TypeError if failed
try:
npdtype = np.dtype(dtype)
except Exception:
# we don't want to force a repr of the non-string
if not isinstance(dtype, str):
raise TypeError("data type not understood")
raise TypeError("data type '{}' not understood".format(
dtype))
# Any invalid dtype (such as pd.Timestamp) should raise an error.
# np.dtype(invalid_type).kind = 0 for such objects. However, this will
# also catch some valid dtypes such as object, np.object_ and 'object'
# which we safeguard against by catching them earlier and returning
# np.dtype(valid_dtype) before this condition is evaluated.
if is_hashable(dtype) and dtype in [object, np.object_, 'object', 'O']:
# check hashability to avoid errors/DeprecationWarning when we get
# here and `dtype` is an array
return npdtype
elif npdtype.kind == 'O':
raise TypeError("dtype '{}' not understood".format(dtype))
return npdtype |
groupby & merge; we are always performing a left-by type operation
Parameters
----------
by: field to group
on: duplicates field
left: left frame
right: right frame
_merge_pieces: function for merging
check_duplicates: boolean, default True
should we check & clean duplicates | def _groupby_and_merge(by, on, left, right, _merge_pieces,
check_duplicates=True):
"""
groupby & merge; we are always performing a left-by type operation
Parameters
----------
by: field to group
on: duplicates field
left: left frame
right: right frame
_merge_pieces: function for merging
check_duplicates: boolean, default True
should we check & clean duplicates
"""
pieces = []
if not isinstance(by, (list, tuple)):
by = [by]
lby = left.groupby(by, sort=False)
# if we can groupby the rhs
# then we can get vastly better perf
try:
# we will check & remove duplicates if indicated
if check_duplicates:
if on is None:
on = []
elif not isinstance(on, (list, tuple)):
on = [on]
if right.duplicated(by + on).any():
right = right.drop_duplicates(by + on, keep='last')
rby = right.groupby(by, sort=False)
except KeyError:
rby = None
for key, lhs in lby:
if rby is None:
rhs = right
else:
try:
rhs = right.take(rby.indices[key])
except KeyError:
# key doesn't exist in left
lcols = lhs.columns.tolist()
cols = lcols + [r for r in right.columns
if r not in set(lcols)]
merged = lhs.reindex(columns=cols)
merged.index = range(len(merged))
pieces.append(merged)
continue
merged = _merge_pieces(lhs, rhs)
# make sure join keys are in the merged
# TODO, should _merge_pieces do this?
for k in by:
try:
if k in merged:
merged[k] = key
except KeyError:
pass
pieces.append(merged)
# preserve the original order
# if we have a missing piece this can be reset
from pandas.core.reshape.concat import concat
result = concat(pieces, ignore_index=True)
result = result.reindex(columns=pieces[0].columns, copy=False)
return result, lby |
Perform merge with optional filling/interpolation designed for ordered
data like time series data. Optionally perform group-wise merge (see
examples)
Parameters
----------
left : DataFrame
right : DataFrame
on : label or list
Field names to join on. Must be found in both DataFrames.
left_on : label or list, or array-like
Field names to join on in left DataFrame. Can be a vector or list of
vectors of the length of the DataFrame to use a particular vector as
the join key instead of columns
right_on : label or list, or array-like
Field names to join on in right DataFrame or vector/list of vectors per
left_on docs
left_by : column name or list of column names
Group left DataFrame by group columns and merge piece by piece with
right DataFrame
right_by : column name or list of column names
Group right DataFrame by group columns and merge piece by piece with
left DataFrame
fill_method : {'ffill', None}, default None
Interpolation method for data
suffixes : Sequence, default is ("_x", "_y")
A length-2 sequence where each element is optionally a string
indicating the suffix to add to overlapping column names in
`left` and `right` respectively. Pass a value of `None` instead
of a string to indicate that the column name from `left` or
`right` should be left as-is, with no suffix. At least one of the
values must not be None.
.. versionchanged:: 0.25.0
how : {'left', 'right', 'outer', 'inner'}, default 'outer'
* left: use only keys from left frame (SQL: left outer join)
* right: use only keys from right frame (SQL: right outer join)
* outer: use union of keys from both frames (SQL: full outer join)
* inner: use intersection of keys from both frames (SQL: inner join)
.. versionadded:: 0.19.0
Returns
-------
merged : DataFrame
The output type will the be same as 'left', if it is a subclass
of DataFrame.
See Also
--------
merge
merge_asof
Examples
--------
>>> A >>> B
key lvalue group key rvalue
0 a 1 a 0 b 1
1 c 2 a 1 c 2
2 e 3 a 2 d 3
3 a 1 b
4 c 2 b
5 e 3 b
>>> merge_ordered(A, B, fill_method='ffill', left_by='group')
group key lvalue rvalue
0 a a 1 NaN
1 a b 1 1.0
2 a c 2 2.0
3 a d 2 3.0
4 a e 3 3.0
5 b a 1 NaN
6 b b 1 1.0
7 b c 2 2.0
8 b d 2 3.0
9 b e 3 3.0 | def merge_ordered(left, right, on=None,
left_on=None, right_on=None,
left_by=None, right_by=None,
fill_method=None, suffixes=('_x', '_y'),
how='outer'):
"""Perform merge with optional filling/interpolation designed for ordered
data like time series data. Optionally perform group-wise merge (see
examples)
Parameters
----------
left : DataFrame
right : DataFrame
on : label or list
Field names to join on. Must be found in both DataFrames.
left_on : label or list, or array-like
Field names to join on in left DataFrame. Can be a vector or list of
vectors of the length of the DataFrame to use a particular vector as
the join key instead of columns
right_on : label or list, or array-like
Field names to join on in right DataFrame or vector/list of vectors per
left_on docs
left_by : column name or list of column names
Group left DataFrame by group columns and merge piece by piece with
right DataFrame
right_by : column name or list of column names
Group right DataFrame by group columns and merge piece by piece with
left DataFrame
fill_method : {'ffill', None}, default None
Interpolation method for data
suffixes : Sequence, default is ("_x", "_y")
A length-2 sequence where each element is optionally a string
indicating the suffix to add to overlapping column names in
`left` and `right` respectively. Pass a value of `None` instead
of a string to indicate that the column name from `left` or
`right` should be left as-is, with no suffix. At least one of the
values must not be None.
.. versionchanged:: 0.25.0
how : {'left', 'right', 'outer', 'inner'}, default 'outer'
* left: use only keys from left frame (SQL: left outer join)
* right: use only keys from right frame (SQL: right outer join)
* outer: use union of keys from both frames (SQL: full outer join)
* inner: use intersection of keys from both frames (SQL: inner join)
.. versionadded:: 0.19.0
Returns
-------
merged : DataFrame
The output type will the be same as 'left', if it is a subclass
of DataFrame.
See Also
--------
merge
merge_asof
Examples
--------
>>> A >>> B
key lvalue group key rvalue
0 a 1 a 0 b 1
1 c 2 a 1 c 2
2 e 3 a 2 d 3
3 a 1 b
4 c 2 b
5 e 3 b
>>> merge_ordered(A, B, fill_method='ffill', left_by='group')
group key lvalue rvalue
0 a a 1 NaN
1 a b 1 1.0
2 a c 2 2.0
3 a d 2 3.0
4 a e 3 3.0
5 b a 1 NaN
6 b b 1 1.0
7 b c 2 2.0
8 b d 2 3.0
9 b e 3 3.0
"""
def _merger(x, y):
# perform the ordered merge operation
op = _OrderedMerge(x, y, on=on, left_on=left_on, right_on=right_on,
suffixes=suffixes, fill_method=fill_method,
how=how)
return op.get_result()
if left_by is not None and right_by is not None:
raise ValueError('Can only group either left or right frames')
elif left_by is not None:
result, _ = _groupby_and_merge(left_by, on, left, right,
lambda x, y: _merger(x, y),
check_duplicates=False)
elif right_by is not None:
result, _ = _groupby_and_merge(right_by, on, right, left,
lambda x, y: _merger(y, x),
check_duplicates=False)
else:
result = _merger(left, right)
return result |
Perform an asof merge. This is similar to a left-join except that we
match on nearest key rather than equal keys.
Both DataFrames must be sorted by the key.
For each row in the left DataFrame:
- A "backward" search selects the last row in the right DataFrame whose
'on' key is less than or equal to the left's key.
- A "forward" search selects the first row in the right DataFrame whose
'on' key is greater than or equal to the left's key.
- A "nearest" search selects the row in the right DataFrame whose 'on'
key is closest in absolute distance to the left's key.
The default is "backward" and is compatible in versions below 0.20.0.
The direction parameter was added in version 0.20.0 and introduces
"forward" and "nearest".
Optionally match on equivalent keys with 'by' before searching with 'on'.
.. versionadded:: 0.19.0
Parameters
----------
left : DataFrame
right : DataFrame
on : label
Field name to join on. Must be found in both DataFrames.
The data MUST be ordered. Furthermore this must be a numeric column,
such as datetimelike, integer, or float. On or left_on/right_on
must be given.
left_on : label
Field name to join on in left DataFrame.
right_on : label
Field name to join on in right DataFrame.
left_index : boolean
Use the index of the left DataFrame as the join key.
.. versionadded:: 0.19.2
right_index : boolean
Use the index of the right DataFrame as the join key.
.. versionadded:: 0.19.2
by : column name or list of column names
Match on these columns before performing merge operation.
left_by : column name
Field names to match on in the left DataFrame.
.. versionadded:: 0.19.2
right_by : column name
Field names to match on in the right DataFrame.
.. versionadded:: 0.19.2
suffixes : 2-length sequence (tuple, list, ...)
Suffix to apply to overlapping column names in the left and right
side, respectively.
tolerance : integer or Timedelta, optional, default None
Select asof tolerance within this range; must be compatible
with the merge index.
allow_exact_matches : boolean, default True
- If True, allow matching with the same 'on' value
(i.e. less-than-or-equal-to / greater-than-or-equal-to)
- If False, don't match the same 'on' value
(i.e., strictly less-than / strictly greater-than)
direction : 'backward' (default), 'forward', or 'nearest'
Whether to search for prior, subsequent, or closest matches.
.. versionadded:: 0.20.0
Returns
-------
merged : DataFrame
See Also
--------
merge
merge_ordered
Examples
--------
>>> left = pd.DataFrame({'a': [1, 5, 10], 'left_val': ['a', 'b', 'c']})
>>> left
a left_val
0 1 a
1 5 b
2 10 c
>>> right = pd.DataFrame({'a': [1, 2, 3, 6, 7],
... 'right_val': [1, 2, 3, 6, 7]})
>>> right
a right_val
0 1 1
1 2 2
2 3 3
3 6 6
4 7 7
>>> pd.merge_asof(left, right, on='a')
a left_val right_val
0 1 a 1
1 5 b 3
2 10 c 7
>>> pd.merge_asof(left, right, on='a', allow_exact_matches=False)
a left_val right_val
0 1 a NaN
1 5 b 3.0
2 10 c 7.0
>>> pd.merge_asof(left, right, on='a', direction='forward')
a left_val right_val
0 1 a 1.0
1 5 b 6.0
2 10 c NaN
>>> pd.merge_asof(left, right, on='a', direction='nearest')
a left_val right_val
0 1 a 1
1 5 b 6
2 10 c 7
We can use indexed DataFrames as well.
>>> left = pd.DataFrame({'left_val': ['a', 'b', 'c']}, index=[1, 5, 10])
>>> left
left_val
1 a
5 b
10 c
>>> right = pd.DataFrame({'right_val': [1, 2, 3, 6, 7]},
... index=[1, 2, 3, 6, 7])
>>> right
right_val
1 1
2 2
3 3
6 6
7 7
>>> pd.merge_asof(left, right, left_index=True, right_index=True)
left_val right_val
1 a 1
5 b 3
10 c 7
Here is a real-world times-series example
>>> quotes
time ticker bid ask
0 2016-05-25 13:30:00.023 GOOG 720.50 720.93
1 2016-05-25 13:30:00.023 MSFT 51.95 51.96
2 2016-05-25 13:30:00.030 MSFT 51.97 51.98
3 2016-05-25 13:30:00.041 MSFT 51.99 52.00
4 2016-05-25 13:30:00.048 GOOG 720.50 720.93
5 2016-05-25 13:30:00.049 AAPL 97.99 98.01
6 2016-05-25 13:30:00.072 GOOG 720.50 720.88
7 2016-05-25 13:30:00.075 MSFT 52.01 52.03
>>> trades
time ticker price quantity
0 2016-05-25 13:30:00.023 MSFT 51.95 75
1 2016-05-25 13:30:00.038 MSFT 51.95 155
2 2016-05-25 13:30:00.048 GOOG 720.77 100
3 2016-05-25 13:30:00.048 GOOG 720.92 100
4 2016-05-25 13:30:00.048 AAPL 98.00 100
By default we are taking the asof of the quotes
>>> pd.merge_asof(trades, quotes,
... on='time',
... by='ticker')
time ticker price quantity bid ask
0 2016-05-25 13:30:00.023 MSFT 51.95 75 51.95 51.96
1 2016-05-25 13:30:00.038 MSFT 51.95 155 51.97 51.98
2 2016-05-25 13:30:00.048 GOOG 720.77 100 720.50 720.93
3 2016-05-25 13:30:00.048 GOOG 720.92 100 720.50 720.93
4 2016-05-25 13:30:00.048 AAPL 98.00 100 NaN NaN
We only asof within 2ms between the quote time and the trade time
>>> pd.merge_asof(trades, quotes,
... on='time',
... by='ticker',
... tolerance=pd.Timedelta('2ms'))
time ticker price quantity bid ask
0 2016-05-25 13:30:00.023 MSFT 51.95 75 51.95 51.96
1 2016-05-25 13:30:00.038 MSFT 51.95 155 NaN NaN
2 2016-05-25 13:30:00.048 GOOG 720.77 100 720.50 720.93
3 2016-05-25 13:30:00.048 GOOG 720.92 100 720.50 720.93
4 2016-05-25 13:30:00.048 AAPL 98.00 100 NaN NaN
We only asof within 10ms between the quote time and the trade time
and we exclude exact matches on time. However *prior* data will
propagate forward
>>> pd.merge_asof(trades, quotes,
... on='time',
... by='ticker',
... tolerance=pd.Timedelta('10ms'),
... allow_exact_matches=False)
time ticker price quantity bid ask
0 2016-05-25 13:30:00.023 MSFT 51.95 75 NaN NaN
1 2016-05-25 13:30:00.038 MSFT 51.95 155 51.97 51.98
2 2016-05-25 13:30:00.048 GOOG 720.77 100 NaN NaN
3 2016-05-25 13:30:00.048 GOOG 720.92 100 NaN NaN
4 2016-05-25 13:30:00.048 AAPL 98.00 100 NaN NaN | def merge_asof(left, right, on=None,
left_on=None, right_on=None,
left_index=False, right_index=False,
by=None, left_by=None, right_by=None,
suffixes=('_x', '_y'),
tolerance=None,
allow_exact_matches=True,
direction='backward'):
"""Perform an asof merge. This is similar to a left-join except that we
match on nearest key rather than equal keys.
Both DataFrames must be sorted by the key.
For each row in the left DataFrame:
- A "backward" search selects the last row in the right DataFrame whose
'on' key is less than or equal to the left's key.
- A "forward" search selects the first row in the right DataFrame whose
'on' key is greater than or equal to the left's key.
- A "nearest" search selects the row in the right DataFrame whose 'on'
key is closest in absolute distance to the left's key.
The default is "backward" and is compatible in versions below 0.20.0.
The direction parameter was added in version 0.20.0 and introduces
"forward" and "nearest".
Optionally match on equivalent keys with 'by' before searching with 'on'.
.. versionadded:: 0.19.0
Parameters
----------
left : DataFrame
right : DataFrame
on : label
Field name to join on. Must be found in both DataFrames.
The data MUST be ordered. Furthermore this must be a numeric column,
such as datetimelike, integer, or float. On or left_on/right_on
must be given.
left_on : label
Field name to join on in left DataFrame.
right_on : label
Field name to join on in right DataFrame.
left_index : boolean
Use the index of the left DataFrame as the join key.
.. versionadded:: 0.19.2
right_index : boolean
Use the index of the right DataFrame as the join key.
.. versionadded:: 0.19.2
by : column name or list of column names
Match on these columns before performing merge operation.
left_by : column name
Field names to match on in the left DataFrame.
.. versionadded:: 0.19.2
right_by : column name
Field names to match on in the right DataFrame.
.. versionadded:: 0.19.2
suffixes : 2-length sequence (tuple, list, ...)
Suffix to apply to overlapping column names in the left and right
side, respectively.
tolerance : integer or Timedelta, optional, default None
Select asof tolerance within this range; must be compatible
with the merge index.
allow_exact_matches : boolean, default True
- If True, allow matching with the same 'on' value
(i.e. less-than-or-equal-to / greater-than-or-equal-to)
- If False, don't match the same 'on' value
(i.e., strictly less-than / strictly greater-than)
direction : 'backward' (default), 'forward', or 'nearest'
Whether to search for prior, subsequent, or closest matches.
.. versionadded:: 0.20.0
Returns
-------
merged : DataFrame
See Also
--------
merge
merge_ordered
Examples
--------
>>> left = pd.DataFrame({'a': [1, 5, 10], 'left_val': ['a', 'b', 'c']})
>>> left
a left_val
0 1 a
1 5 b
2 10 c
>>> right = pd.DataFrame({'a': [1, 2, 3, 6, 7],
... 'right_val': [1, 2, 3, 6, 7]})
>>> right
a right_val
0 1 1
1 2 2
2 3 3
3 6 6
4 7 7
>>> pd.merge_asof(left, right, on='a')
a left_val right_val
0 1 a 1
1 5 b 3
2 10 c 7
>>> pd.merge_asof(left, right, on='a', allow_exact_matches=False)
a left_val right_val
0 1 a NaN
1 5 b 3.0
2 10 c 7.0
>>> pd.merge_asof(left, right, on='a', direction='forward')
a left_val right_val
0 1 a 1.0
1 5 b 6.0
2 10 c NaN
>>> pd.merge_asof(left, right, on='a', direction='nearest')
a left_val right_val
0 1 a 1
1 5 b 6
2 10 c 7
We can use indexed DataFrames as well.
>>> left = pd.DataFrame({'left_val': ['a', 'b', 'c']}, index=[1, 5, 10])
>>> left
left_val
1 a
5 b
10 c
>>> right = pd.DataFrame({'right_val': [1, 2, 3, 6, 7]},
... index=[1, 2, 3, 6, 7])
>>> right
right_val
1 1
2 2
3 3
6 6
7 7
>>> pd.merge_asof(left, right, left_index=True, right_index=True)
left_val right_val
1 a 1
5 b 3
10 c 7
Here is a real-world times-series example
>>> quotes
time ticker bid ask
0 2016-05-25 13:30:00.023 GOOG 720.50 720.93
1 2016-05-25 13:30:00.023 MSFT 51.95 51.96
2 2016-05-25 13:30:00.030 MSFT 51.97 51.98
3 2016-05-25 13:30:00.041 MSFT 51.99 52.00
4 2016-05-25 13:30:00.048 GOOG 720.50 720.93
5 2016-05-25 13:30:00.049 AAPL 97.99 98.01
6 2016-05-25 13:30:00.072 GOOG 720.50 720.88
7 2016-05-25 13:30:00.075 MSFT 52.01 52.03
>>> trades
time ticker price quantity
0 2016-05-25 13:30:00.023 MSFT 51.95 75
1 2016-05-25 13:30:00.038 MSFT 51.95 155
2 2016-05-25 13:30:00.048 GOOG 720.77 100
3 2016-05-25 13:30:00.048 GOOG 720.92 100
4 2016-05-25 13:30:00.048 AAPL 98.00 100
By default we are taking the asof of the quotes
>>> pd.merge_asof(trades, quotes,
... on='time',
... by='ticker')
time ticker price quantity bid ask
0 2016-05-25 13:30:00.023 MSFT 51.95 75 51.95 51.96
1 2016-05-25 13:30:00.038 MSFT 51.95 155 51.97 51.98
2 2016-05-25 13:30:00.048 GOOG 720.77 100 720.50 720.93
3 2016-05-25 13:30:00.048 GOOG 720.92 100 720.50 720.93
4 2016-05-25 13:30:00.048 AAPL 98.00 100 NaN NaN
We only asof within 2ms between the quote time and the trade time
>>> pd.merge_asof(trades, quotes,
... on='time',
... by='ticker',
... tolerance=pd.Timedelta('2ms'))
time ticker price quantity bid ask
0 2016-05-25 13:30:00.023 MSFT 51.95 75 51.95 51.96
1 2016-05-25 13:30:00.038 MSFT 51.95 155 NaN NaN
2 2016-05-25 13:30:00.048 GOOG 720.77 100 720.50 720.93
3 2016-05-25 13:30:00.048 GOOG 720.92 100 720.50 720.93
4 2016-05-25 13:30:00.048 AAPL 98.00 100 NaN NaN
We only asof within 10ms between the quote time and the trade time
and we exclude exact matches on time. However *prior* data will
propagate forward
>>> pd.merge_asof(trades, quotes,
... on='time',
... by='ticker',
... tolerance=pd.Timedelta('10ms'),
... allow_exact_matches=False)
time ticker price quantity bid ask
0 2016-05-25 13:30:00.023 MSFT 51.95 75 NaN NaN
1 2016-05-25 13:30:00.038 MSFT 51.95 155 51.97 51.98
2 2016-05-25 13:30:00.048 GOOG 720.77 100 NaN NaN
3 2016-05-25 13:30:00.048 GOOG 720.92 100 NaN NaN
4 2016-05-25 13:30:00.048 AAPL 98.00 100 NaN NaN
"""
op = _AsOfMerge(left, right,
on=on, left_on=left_on, right_on=right_on,
left_index=left_index, right_index=right_index,
by=by, left_by=left_by, right_by=right_by,
suffixes=suffixes,
how='asof', tolerance=tolerance,
allow_exact_matches=allow_exact_matches,
direction=direction)
return op.get_result() |
*this is an internal non-public method*
Returns the levels, labels and names of a multi-index to multi-index join.
Depending on the type of join, this method restores the appropriate
dropped levels of the joined multi-index.
The method relies on lidx, rindexer which hold the index positions of
left and right, where a join was feasible
Parameters
----------
left : MultiIndex
left index
right : MultiIndex
right index
dropped_level_names : str array
list of non-common level names
join_index : MultiIndex
the index of the join between the
common levels of left and right
lindexer : intp array
left indexer
rindexer : intp array
right indexer
Returns
-------
levels : list of Index
levels of combined multiindexes
labels : intp array
labels of combined multiindexes
names : str array
names of combined multiindexes | def _restore_dropped_levels_multijoin(left, right, dropped_level_names,
join_index, lindexer, rindexer):
"""
*this is an internal non-public method*
Returns the levels, labels and names of a multi-index to multi-index join.
Depending on the type of join, this method restores the appropriate
dropped levels of the joined multi-index.
The method relies on lidx, rindexer which hold the index positions of
left and right, where a join was feasible
Parameters
----------
left : MultiIndex
left index
right : MultiIndex
right index
dropped_level_names : str array
list of non-common level names
join_index : MultiIndex
the index of the join between the
common levels of left and right
lindexer : intp array
left indexer
rindexer : intp array
right indexer
Returns
-------
levels : list of Index
levels of combined multiindexes
labels : intp array
labels of combined multiindexes
names : str array
names of combined multiindexes
"""
def _convert_to_mulitindex(index):
if isinstance(index, MultiIndex):
return index
else:
return MultiIndex.from_arrays([index.values],
names=[index.name])
# For multi-multi joins with one overlapping level,
# the returned index if of type Index
# Assure that join_index is of type MultiIndex
# so that dropped levels can be appended
join_index = _convert_to_mulitindex(join_index)
join_levels = join_index.levels
join_codes = join_index.codes
join_names = join_index.names
# lindexer and rindexer hold the indexes where the join occurred
# for left and right respectively. If left/right is None then
# the join occurred on all indices of left/right
if lindexer is None:
lindexer = range(left.size)
if rindexer is None:
rindexer = range(right.size)
# Iterate through the levels that must be restored
for dropped_level_name in dropped_level_names:
if dropped_level_name in left.names:
idx = left
indexer = lindexer
else:
idx = right
indexer = rindexer
# The index of the level name to be restored
name_idx = idx.names.index(dropped_level_name)
restore_levels = idx.levels[name_idx]
# Inject -1 in the codes list where a join was not possible
# IOW indexer[i]=-1
codes = idx.codes[name_idx]
restore_codes = algos.take_nd(codes, indexer, fill_value=-1)
join_levels = join_levels + [restore_levels]
join_codes = join_codes + [restore_codes]
join_names = join_names + [dropped_level_name]
return join_levels, join_codes, join_names |
Restore index levels specified as `on` parameters
Here we check for cases where `self.left_on` and `self.right_on` pairs
each reference an index level in their respective DataFrames. The
joined columns corresponding to these pairs are then restored to the
index of `result`.
**Note:** This method has side effects. It modifies `result` in-place
Parameters
----------
result: DataFrame
merge result
Returns
-------
None | def _maybe_restore_index_levels(self, result):
"""
Restore index levels specified as `on` parameters
Here we check for cases where `self.left_on` and `self.right_on` pairs
each reference an index level in their respective DataFrames. The
joined columns corresponding to these pairs are then restored to the
index of `result`.
**Note:** This method has side effects. It modifies `result` in-place
Parameters
----------
result: DataFrame
merge result
Returns
-------
None
"""
names_to_restore = []
for name, left_key, right_key in zip(self.join_names,
self.left_on,
self.right_on):
if (self.orig_left._is_level_reference(left_key) and
self.orig_right._is_level_reference(right_key) and
name not in result.index.names):
names_to_restore.append(name)
if names_to_restore:
result.set_index(names_to_restore, inplace=True) |
return the join indexers | def _get_join_indexers(self):
""" return the join indexers """
return _get_join_indexers(self.left_join_keys,
self.right_join_keys,
sort=self.sort,
how=self.how) |
Create a join index by rearranging one index to match another
Parameters
----------
index: Index being rearranged
other_index: Index used to supply values not found in index
indexer: how to rearrange index
how: replacement is only necessary if indexer based on other_index
Returns
-------
join_index | def _create_join_index(self, index, other_index, indexer,
other_indexer, how='left'):
"""
Create a join index by rearranging one index to match another
Parameters
----------
index: Index being rearranged
other_index: Index used to supply values not found in index
indexer: how to rearrange index
how: replacement is only necessary if indexer based on other_index
Returns
-------
join_index
"""
join_index = index.take(indexer)
if (self.how in (how, 'outer') and
not isinstance(other_index, MultiIndex)):
# if final index requires values in other_index but not target
# index, indexer may hold missing (-1) values, causing Index.take
# to take the final value in target index
mask = indexer == -1
if np.any(mask):
# if values missing (-1) from target index,
# take from other_index instead
join_list = join_index.to_numpy()
other_list = other_index.take(other_indexer).to_numpy()
join_list[mask] = other_list[mask]
join_index = Index(join_list, dtype=join_index.dtype,
name=join_index.name)
return join_index |
Note: has side effects (copy/delete key columns)
Parameters
----------
left
right
on
Returns
-------
left_keys, right_keys | def _get_merge_keys(self):
"""
Note: has side effects (copy/delete key columns)
Parameters
----------
left
right
on
Returns
-------
left_keys, right_keys
"""
left_keys = []
right_keys = []
join_names = []
right_drop = []
left_drop = []
left, right = self.left, self.right
is_lkey = lambda x: is_array_like(x) and len(x) == len(left)
is_rkey = lambda x: is_array_like(x) and len(x) == len(right)
# Note that pd.merge_asof() has separate 'on' and 'by' parameters. A
# user could, for example, request 'left_index' and 'left_by'. In a
# regular pd.merge(), users cannot specify both 'left_index' and
# 'left_on'. (Instead, users have a MultiIndex). That means the
# self.left_on in this function is always empty in a pd.merge(), but
# a pd.merge_asof(left_index=True, left_by=...) will result in a
# self.left_on array with a None in the middle of it. This requires
# a work-around as designated in the code below.
# See _validate_specification() for where this happens.
# ugh, spaghetti re #733
if _any(self.left_on) and _any(self.right_on):
for lk, rk in zip(self.left_on, self.right_on):
if is_lkey(lk):
left_keys.append(lk)
if is_rkey(rk):
right_keys.append(rk)
join_names.append(None) # what to do?
else:
if rk is not None:
right_keys.append(
right._get_label_or_level_values(rk))
join_names.append(rk)
else:
# work-around for merge_asof(right_index=True)
right_keys.append(right.index)
join_names.append(right.index.name)
else:
if not is_rkey(rk):
if rk is not None:
right_keys.append(
right._get_label_or_level_values(rk))
else:
# work-around for merge_asof(right_index=True)
right_keys.append(right.index)
if lk is not None and lk == rk:
# avoid key upcast in corner case (length-0)
if len(left) > 0:
right_drop.append(rk)
else:
left_drop.append(lk)
else:
right_keys.append(rk)
if lk is not None:
left_keys.append(left._get_label_or_level_values(lk))
join_names.append(lk)
else:
# work-around for merge_asof(left_index=True)
left_keys.append(left.index)
join_names.append(left.index.name)
elif _any(self.left_on):
for k in self.left_on:
if is_lkey(k):
left_keys.append(k)
join_names.append(None)
else:
left_keys.append(left._get_label_or_level_values(k))
join_names.append(k)
if isinstance(self.right.index, MultiIndex):
right_keys = [lev._values.take(lev_codes) for lev, lev_codes
in zip(self.right.index.levels,
self.right.index.codes)]
else:
right_keys = [self.right.index._values]
elif _any(self.right_on):
for k in self.right_on:
if is_rkey(k):
right_keys.append(k)
join_names.append(None)
else:
right_keys.append(right._get_label_or_level_values(k))
join_names.append(k)
if isinstance(self.left.index, MultiIndex):
left_keys = [lev._values.take(lev_codes) for lev, lev_codes
in zip(self.left.index.levels,
self.left.index.codes)]
else:
left_keys = [self.left.index.values]
if left_drop:
self.left = self.left._drop_labels_or_levels(left_drop)
if right_drop:
self.right = self.right._drop_labels_or_levels(right_drop)
return left_keys, right_keys, join_names |
return the join indexers | def _get_join_indexers(self):
""" return the join indexers """
def flip(xs):
""" unlike np.transpose, this returns an array of tuples """
labels = list(string.ascii_lowercase[:len(xs)])
dtypes = [x.dtype for x in xs]
labeled_dtypes = list(zip(labels, dtypes))
return np.array(lzip(*xs), labeled_dtypes)
# values to compare
left_values = (self.left.index.values if self.left_index else
self.left_join_keys[-1])
right_values = (self.right.index.values if self.right_index else
self.right_join_keys[-1])
tolerance = self.tolerance
# we require sortedness and non-null values in the join keys
msg_sorted = "{side} keys must be sorted"
msg_missings = "Merge keys contain null values on {side} side"
if not Index(left_values).is_monotonic:
if isnull(left_values).any():
raise ValueError(msg_missings.format(side='left'))
else:
raise ValueError(msg_sorted.format(side='left'))
if not Index(right_values).is_monotonic:
if isnull(right_values).any():
raise ValueError(msg_missings.format(side='right'))
else:
raise ValueError(msg_sorted.format(side='right'))
# initial type conversion as needed
if needs_i8_conversion(left_values):
left_values = left_values.view('i8')
right_values = right_values.view('i8')
if tolerance is not None:
tolerance = tolerance.value
# a "by" parameter requires special handling
if self.left_by is not None:
# remove 'on' parameter from values if one existed
if self.left_index and self.right_index:
left_by_values = self.left_join_keys
right_by_values = self.right_join_keys
else:
left_by_values = self.left_join_keys[0:-1]
right_by_values = self.right_join_keys[0:-1]
# get tuple representation of values if more than one
if len(left_by_values) == 1:
left_by_values = left_by_values[0]
right_by_values = right_by_values[0]
else:
left_by_values = flip(left_by_values)
right_by_values = flip(right_by_values)
# upcast 'by' parameter because HashTable is limited
by_type = _get_cython_type_upcast(left_by_values.dtype)
by_type_caster = _type_casters[by_type]
left_by_values = by_type_caster(left_by_values)
right_by_values = by_type_caster(right_by_values)
# choose appropriate function by type
func = _asof_by_function(self.direction)
return func(left_values,
right_values,
left_by_values,
right_by_values,
self.allow_exact_matches,
tolerance)
else:
# choose appropriate function by type
func = _asof_function(self.direction)
return func(left_values,
right_values,
self.allow_exact_matches,
tolerance) |
Check if we match 'dtype'.
Parameters
----------
dtype : object
The object to check.
Returns
-------
is_dtype : bool
Notes
-----
The default implementation is True if
1. ``cls.construct_from_string(dtype)`` is an instance
of ``cls``.
2. ``dtype`` is an object and is an instance of ``cls``
3. ``dtype`` has a ``dtype`` attribute, and any of the above
conditions is true for ``dtype.dtype``. | def is_dtype(cls, dtype):
"""Check if we match 'dtype'.
Parameters
----------
dtype : object
The object to check.
Returns
-------
is_dtype : bool
Notes
-----
The default implementation is True if
1. ``cls.construct_from_string(dtype)`` is an instance
of ``cls``.
2. ``dtype`` is an object and is an instance of ``cls``
3. ``dtype`` has a ``dtype`` attribute, and any of the above
conditions is true for ``dtype.dtype``.
"""
dtype = getattr(dtype, 'dtype', dtype)
if isinstance(dtype, (ABCSeries, ABCIndexClass,
ABCDataFrame, np.dtype)):
# https://github.com/pandas-dev/pandas/issues/22960
# avoid passing data to `construct_from_string`. This could
# cause a FutureWarning from numpy about failing elementwise
# comparison from, e.g., comparing DataFrame == 'category'.
return False
elif dtype is None:
return False
elif isinstance(dtype, cls):
return True
try:
return cls.construct_from_string(dtype) is not None
except TypeError:
return False |
Auxiliary function for :meth:`str.cat`
Parameters
----------
list_of_columns : list of numpy arrays
List of arrays to be concatenated with sep;
these arrays may not contain NaNs!
sep : string
The separator string for concatenating the columns
Returns
-------
nd.array
The concatenation of list_of_columns with sep | def cat_core(list_of_columns, sep):
"""
Auxiliary function for :meth:`str.cat`
Parameters
----------
list_of_columns : list of numpy arrays
List of arrays to be concatenated with sep;
these arrays may not contain NaNs!
sep : string
The separator string for concatenating the columns
Returns
-------
nd.array
The concatenation of list_of_columns with sep
"""
list_with_sep = [sep] * (2 * len(list_of_columns) - 1)
list_with_sep[::2] = list_of_columns
return np.sum(list_with_sep, axis=0) |
Count occurrences of pattern in each string of the Series/Index.
This function is used to count the number of times a particular regex
pattern is repeated in each of the string elements of the
:class:`~pandas.Series`.
Parameters
----------
pat : str
Valid regular expression.
flags : int, default 0, meaning no flags
Flags for the `re` module. For a complete list, `see here
<https://docs.python.org/3/howto/regex.html#compilation-flags>`_.
**kwargs
For compatibility with other string methods. Not used.
Returns
-------
Series or Index
Same type as the calling object containing the integer counts.
See Also
--------
re : Standard library module for regular expressions.
str.count : Standard library version, without regular expression support.
Notes
-----
Some characters need to be escaped when passing in `pat`.
eg. ``'$'`` has a special meaning in regex and must be escaped when
finding this literal character.
Examples
--------
>>> s = pd.Series(['A', 'B', 'Aaba', 'Baca', np.nan, 'CABA', 'cat'])
>>> s.str.count('a')
0 0.0
1 0.0
2 2.0
3 2.0
4 NaN
5 0.0
6 1.0
dtype: float64
Escape ``'$'`` to find the literal dollar sign.
>>> s = pd.Series(['$', 'B', 'Aab$', '$$ca', 'C$B$', 'cat'])
>>> s.str.count('\\$')
0 1
1 0
2 1
3 2
4 2
5 0
dtype: int64
This is also available on Index
>>> pd.Index(['A', 'A', 'Aaba', 'cat']).str.count('a')
Int64Index([0, 0, 2, 1], dtype='int64') | def str_count(arr, pat, flags=0):
"""
Count occurrences of pattern in each string of the Series/Index.
This function is used to count the number of times a particular regex
pattern is repeated in each of the string elements of the
:class:`~pandas.Series`.
Parameters
----------
pat : str
Valid regular expression.
flags : int, default 0, meaning no flags
Flags for the `re` module. For a complete list, `see here
<https://docs.python.org/3/howto/regex.html#compilation-flags>`_.
**kwargs
For compatibility with other string methods. Not used.
Returns
-------
Series or Index
Same type as the calling object containing the integer counts.
See Also
--------
re : Standard library module for regular expressions.
str.count : Standard library version, without regular expression support.
Notes
-----
Some characters need to be escaped when passing in `pat`.
eg. ``'$'`` has a special meaning in regex and must be escaped when
finding this literal character.
Examples
--------
>>> s = pd.Series(['A', 'B', 'Aaba', 'Baca', np.nan, 'CABA', 'cat'])
>>> s.str.count('a')
0 0.0
1 0.0
2 2.0
3 2.0
4 NaN
5 0.0
6 1.0
dtype: float64
Escape ``'$'`` to find the literal dollar sign.
>>> s = pd.Series(['$', 'B', 'Aab$', '$$ca', 'C$B$', 'cat'])
>>> s.str.count('\\$')
0 1
1 0
2 1
3 2
4 2
5 0
dtype: int64
This is also available on Index
>>> pd.Index(['A', 'A', 'Aaba', 'cat']).str.count('a')
Int64Index([0, 0, 2, 1], dtype='int64')
"""
regex = re.compile(pat, flags=flags)
f = lambda x: len(regex.findall(x))
return _na_map(f, arr, dtype=int) |
Test if pattern or regex is contained within a string of a Series or Index.
Return boolean Series or Index based on whether a given pattern or regex is
contained within a string of a Series or Index.
Parameters
----------
pat : str
Character sequence or regular expression.
case : bool, default True
If True, case sensitive.
flags : int, default 0 (no flags)
Flags to pass through to the re module, e.g. re.IGNORECASE.
na : default NaN
Fill value for missing values.
regex : bool, default True
If True, assumes the pat is a regular expression.
If False, treats the pat as a literal string.
Returns
-------
Series or Index of boolean values
A Series or Index of boolean values indicating whether the
given pattern is contained within the string of each element
of the Series or Index.
See Also
--------
match : Analogous, but stricter, relying on re.match instead of re.search.
Series.str.startswith : Test if the start of each string element matches a
pattern.
Series.str.endswith : Same as startswith, but tests the end of string.
Examples
--------
Returning a Series of booleans using only a literal pattern.
>>> s1 = pd.Series(['Mouse', 'dog', 'house and parrot', '23', np.NaN])
>>> s1.str.contains('og', regex=False)
0 False
1 True
2 False
3 False
4 NaN
dtype: object
Returning an Index of booleans using only a literal pattern.
>>> ind = pd.Index(['Mouse', 'dog', 'house and parrot', '23.0', np.NaN])
>>> ind.str.contains('23', regex=False)
Index([False, False, False, True, nan], dtype='object')
Specifying case sensitivity using `case`.
>>> s1.str.contains('oG', case=True, regex=True)
0 False
1 False
2 False
3 False
4 NaN
dtype: object
Specifying `na` to be `False` instead of `NaN` replaces NaN values
with `False`. If Series or Index does not contain NaN values
the resultant dtype will be `bool`, otherwise, an `object` dtype.
>>> s1.str.contains('og', na=False, regex=True)
0 False
1 True
2 False
3 False
4 False
dtype: bool
Returning 'house' or 'dog' when either expression occurs in a string.
>>> s1.str.contains('house|dog', regex=True)
0 False
1 True
2 True
3 False
4 NaN
dtype: object
Ignoring case sensitivity using `flags` with regex.
>>> import re
>>> s1.str.contains('PARROT', flags=re.IGNORECASE, regex=True)
0 False
1 False
2 True
3 False
4 NaN
dtype: object
Returning any digit using regular expression.
>>> s1.str.contains('\\d', regex=True)
0 False
1 False
2 False
3 True
4 NaN
dtype: object
Ensure `pat` is a not a literal pattern when `regex` is set to True.
Note in the following example one might expect only `s2[1]` and `s2[3]` to
return `True`. However, '.0' as a regex matches any character
followed by a 0.
>>> s2 = pd.Series(['40', '40.0', '41', '41.0', '35'])
>>> s2.str.contains('.0', regex=True)
0 True
1 True
2 False
3 True
4 False
dtype: bool | def str_contains(arr, pat, case=True, flags=0, na=np.nan, regex=True):
"""
Test if pattern or regex is contained within a string of a Series or Index.
Return boolean Series or Index based on whether a given pattern or regex is
contained within a string of a Series or Index.
Parameters
----------
pat : str
Character sequence or regular expression.
case : bool, default True
If True, case sensitive.
flags : int, default 0 (no flags)
Flags to pass through to the re module, e.g. re.IGNORECASE.
na : default NaN
Fill value for missing values.
regex : bool, default True
If True, assumes the pat is a regular expression.
If False, treats the pat as a literal string.
Returns
-------
Series or Index of boolean values
A Series or Index of boolean values indicating whether the
given pattern is contained within the string of each element
of the Series or Index.
See Also
--------
match : Analogous, but stricter, relying on re.match instead of re.search.
Series.str.startswith : Test if the start of each string element matches a
pattern.
Series.str.endswith : Same as startswith, but tests the end of string.
Examples
--------
Returning a Series of booleans using only a literal pattern.
>>> s1 = pd.Series(['Mouse', 'dog', 'house and parrot', '23', np.NaN])
>>> s1.str.contains('og', regex=False)
0 False
1 True
2 False
3 False
4 NaN
dtype: object
Returning an Index of booleans using only a literal pattern.
>>> ind = pd.Index(['Mouse', 'dog', 'house and parrot', '23.0', np.NaN])
>>> ind.str.contains('23', regex=False)
Index([False, False, False, True, nan], dtype='object')
Specifying case sensitivity using `case`.
>>> s1.str.contains('oG', case=True, regex=True)
0 False
1 False
2 False
3 False
4 NaN
dtype: object
Specifying `na` to be `False` instead of `NaN` replaces NaN values
with `False`. If Series or Index does not contain NaN values
the resultant dtype will be `bool`, otherwise, an `object` dtype.
>>> s1.str.contains('og', na=False, regex=True)
0 False
1 True
2 False
3 False
4 False
dtype: bool
Returning 'house' or 'dog' when either expression occurs in a string.
>>> s1.str.contains('house|dog', regex=True)
0 False
1 True
2 True
3 False
4 NaN
dtype: object
Ignoring case sensitivity using `flags` with regex.
>>> import re
>>> s1.str.contains('PARROT', flags=re.IGNORECASE, regex=True)
0 False
1 False
2 True
3 False
4 NaN
dtype: object
Returning any digit using regular expression.
>>> s1.str.contains('\\d', regex=True)
0 False
1 False
2 False
3 True
4 NaN
dtype: object
Ensure `pat` is a not a literal pattern when `regex` is set to True.
Note in the following example one might expect only `s2[1]` and `s2[3]` to
return `True`. However, '.0' as a regex matches any character
followed by a 0.
>>> s2 = pd.Series(['40', '40.0', '41', '41.0', '35'])
>>> s2.str.contains('.0', regex=True)
0 True
1 True
2 False
3 True
4 False
dtype: bool
"""
if regex:
if not case:
flags |= re.IGNORECASE
regex = re.compile(pat, flags=flags)
if regex.groups > 0:
warnings.warn("This pattern has match groups. To actually get the"
" groups, use str.extract.", UserWarning,
stacklevel=3)
f = lambda x: bool(regex.search(x))
else:
if case:
f = lambda x: pat in x
else:
upper_pat = pat.upper()
f = lambda x: upper_pat in x
uppered = _na_map(lambda x: x.upper(), arr)
return _na_map(f, uppered, na, dtype=bool)
return _na_map(f, arr, na, dtype=bool) |
Test if the start of each string element matches a pattern.
Equivalent to :meth:`str.startswith`.
Parameters
----------
pat : str
Character sequence. Regular expressions are not accepted.
na : object, default NaN
Object shown if element tested is not a string.
Returns
-------
Series or Index of bool
A Series of booleans indicating whether the given pattern matches
the start of each string element.
See Also
--------
str.startswith : Python standard library string method.
Series.str.endswith : Same as startswith, but tests the end of string.
Series.str.contains : Tests if string element contains a pattern.
Examples
--------
>>> s = pd.Series(['bat', 'Bear', 'cat', np.nan])
>>> s
0 bat
1 Bear
2 cat
3 NaN
dtype: object
>>> s.str.startswith('b')
0 True
1 False
2 False
3 NaN
dtype: object
Specifying `na` to be `False` instead of `NaN`.
>>> s.str.startswith('b', na=False)
0 True
1 False
2 False
3 False
dtype: bool | def str_startswith(arr, pat, na=np.nan):
"""
Test if the start of each string element matches a pattern.
Equivalent to :meth:`str.startswith`.
Parameters
----------
pat : str
Character sequence. Regular expressions are not accepted.
na : object, default NaN
Object shown if element tested is not a string.
Returns
-------
Series or Index of bool
A Series of booleans indicating whether the given pattern matches
the start of each string element.
See Also
--------
str.startswith : Python standard library string method.
Series.str.endswith : Same as startswith, but tests the end of string.
Series.str.contains : Tests if string element contains a pattern.
Examples
--------
>>> s = pd.Series(['bat', 'Bear', 'cat', np.nan])
>>> s
0 bat
1 Bear
2 cat
3 NaN
dtype: object
>>> s.str.startswith('b')
0 True
1 False
2 False
3 NaN
dtype: object
Specifying `na` to be `False` instead of `NaN`.
>>> s.str.startswith('b', na=False)
0 True
1 False
2 False
3 False
dtype: bool
"""
f = lambda x: x.startswith(pat)
return _na_map(f, arr, na, dtype=bool) |
Test if the end of each string element matches a pattern.
Equivalent to :meth:`str.endswith`.
Parameters
----------
pat : str
Character sequence. Regular expressions are not accepted.
na : object, default NaN
Object shown if element tested is not a string.
Returns
-------
Series or Index of bool
A Series of booleans indicating whether the given pattern matches
the end of each string element.
See Also
--------
str.endswith : Python standard library string method.
Series.str.startswith : Same as endswith, but tests the start of string.
Series.str.contains : Tests if string element contains a pattern.
Examples
--------
>>> s = pd.Series(['bat', 'bear', 'caT', np.nan])
>>> s
0 bat
1 bear
2 caT
3 NaN
dtype: object
>>> s.str.endswith('t')
0 True
1 False
2 False
3 NaN
dtype: object
Specifying `na` to be `False` instead of `NaN`.
>>> s.str.endswith('t', na=False)
0 True
1 False
2 False
3 False
dtype: bool | def str_endswith(arr, pat, na=np.nan):
"""
Test if the end of each string element matches a pattern.
Equivalent to :meth:`str.endswith`.
Parameters
----------
pat : str
Character sequence. Regular expressions are not accepted.
na : object, default NaN
Object shown if element tested is not a string.
Returns
-------
Series or Index of bool
A Series of booleans indicating whether the given pattern matches
the end of each string element.
See Also
--------
str.endswith : Python standard library string method.
Series.str.startswith : Same as endswith, but tests the start of string.
Series.str.contains : Tests if string element contains a pattern.
Examples
--------
>>> s = pd.Series(['bat', 'bear', 'caT', np.nan])
>>> s
0 bat
1 bear
2 caT
3 NaN
dtype: object
>>> s.str.endswith('t')
0 True
1 False
2 False
3 NaN
dtype: object
Specifying `na` to be `False` instead of `NaN`.
>>> s.str.endswith('t', na=False)
0 True
1 False
2 False
3 False
dtype: bool
"""
f = lambda x: x.endswith(pat)
return _na_map(f, arr, na, dtype=bool) |
r"""
Replace occurrences of pattern/regex in the Series/Index with
some other string. Equivalent to :meth:`str.replace` or
:func:`re.sub`.
Parameters
----------
pat : str or compiled regex
String can be a character sequence or regular expression.
.. versionadded:: 0.20.0
`pat` also accepts a compiled regex.
repl : str or callable
Replacement string or a callable. The callable is passed the regex
match object and must return a replacement string to be used.
See :func:`re.sub`.
.. versionadded:: 0.20.0
`repl` also accepts a callable.
n : int, default -1 (all)
Number of replacements to make from start.
case : bool, default None
- If True, case sensitive (the default if `pat` is a string)
- Set to False for case insensitive
- Cannot be set if `pat` is a compiled regex
flags : int, default 0 (no flags)
- re module flags, e.g. re.IGNORECASE
- Cannot be set if `pat` is a compiled regex
regex : bool, default True
- If True, assumes the passed-in pattern is a regular expression.
- If False, treats the pattern as a literal string
- Cannot be set to False if `pat` is a compiled regex or `repl` is
a callable.
.. versionadded:: 0.23.0
Returns
-------
Series or Index of object
A copy of the object with all matching occurrences of `pat` replaced by
`repl`.
Raises
------
ValueError
* if `regex` is False and `repl` is a callable or `pat` is a compiled
regex
* if `pat` is a compiled regex and `case` or `flags` is set
Notes
-----
When `pat` is a compiled regex, all flags should be included in the
compiled regex. Use of `case`, `flags`, or `regex=False` with a compiled
regex will raise an error.
Examples
--------
When `pat` is a string and `regex` is True (the default), the given `pat`
is compiled as a regex. When `repl` is a string, it replaces matching
regex patterns as with :meth:`re.sub`. NaN value(s) in the Series are
left as is:
>>> pd.Series(['foo', 'fuz', np.nan]).str.replace('f.', 'ba', regex=True)
0 bao
1 baz
2 NaN
dtype: object
When `pat` is a string and `regex` is False, every `pat` is replaced with
`repl` as with :meth:`str.replace`:
>>> pd.Series(['f.o', 'fuz', np.nan]).str.replace('f.', 'ba', regex=False)
0 bao
1 fuz
2 NaN
dtype: object
When `repl` is a callable, it is called on every `pat` using
:func:`re.sub`. The callable should expect one positional argument
(a regex object) and return a string.
To get the idea:
>>> pd.Series(['foo', 'fuz', np.nan]).str.replace('f', repr)
0 <_sre.SRE_Match object; span=(0, 1), match='f'>oo
1 <_sre.SRE_Match object; span=(0, 1), match='f'>uz
2 NaN
dtype: object
Reverse every lowercase alphabetic word:
>>> repl = lambda m: m.group(0)[::-1]
>>> pd.Series(['foo 123', 'bar baz', np.nan]).str.replace(r'[a-z]+', repl)
0 oof 123
1 rab zab
2 NaN
dtype: object
Using regex groups (extract second group and swap case):
>>> pat = r"(?P<one>\w+) (?P<two>\w+) (?P<three>\w+)"
>>> repl = lambda m: m.group('two').swapcase()
>>> pd.Series(['One Two Three', 'Foo Bar Baz']).str.replace(pat, repl)
0 tWO
1 bAR
dtype: object
Using a compiled regex with flags
>>> import re
>>> regex_pat = re.compile(r'FUZ', flags=re.IGNORECASE)
>>> pd.Series(['foo', 'fuz', np.nan]).str.replace(regex_pat, 'bar')
0 foo
1 bar
2 NaN
dtype: object | def str_replace(arr, pat, repl, n=-1, case=None, flags=0, regex=True):
r"""
Replace occurrences of pattern/regex in the Series/Index with
some other string. Equivalent to :meth:`str.replace` or
:func:`re.sub`.
Parameters
----------
pat : str or compiled regex
String can be a character sequence or regular expression.
.. versionadded:: 0.20.0
`pat` also accepts a compiled regex.
repl : str or callable
Replacement string or a callable. The callable is passed the regex
match object and must return a replacement string to be used.
See :func:`re.sub`.
.. versionadded:: 0.20.0
`repl` also accepts a callable.
n : int, default -1 (all)
Number of replacements to make from start.
case : bool, default None
- If True, case sensitive (the default if `pat` is a string)
- Set to False for case insensitive
- Cannot be set if `pat` is a compiled regex
flags : int, default 0 (no flags)
- re module flags, e.g. re.IGNORECASE
- Cannot be set if `pat` is a compiled regex
regex : bool, default True
- If True, assumes the passed-in pattern is a regular expression.
- If False, treats the pattern as a literal string
- Cannot be set to False if `pat` is a compiled regex or `repl` is
a callable.
.. versionadded:: 0.23.0
Returns
-------
Series or Index of object
A copy of the object with all matching occurrences of `pat` replaced by
`repl`.
Raises
------
ValueError
* if `regex` is False and `repl` is a callable or `pat` is a compiled
regex
* if `pat` is a compiled regex and `case` or `flags` is set
Notes
-----
When `pat` is a compiled regex, all flags should be included in the
compiled regex. Use of `case`, `flags`, or `regex=False` with a compiled
regex will raise an error.
Examples
--------
When `pat` is a string and `regex` is True (the default), the given `pat`
is compiled as a regex. When `repl` is a string, it replaces matching
regex patterns as with :meth:`re.sub`. NaN value(s) in the Series are
left as is:
>>> pd.Series(['foo', 'fuz', np.nan]).str.replace('f.', 'ba', regex=True)
0 bao
1 baz
2 NaN
dtype: object
When `pat` is a string and `regex` is False, every `pat` is replaced with
`repl` as with :meth:`str.replace`:
>>> pd.Series(['f.o', 'fuz', np.nan]).str.replace('f.', 'ba', regex=False)
0 bao
1 fuz
2 NaN
dtype: object
When `repl` is a callable, it is called on every `pat` using
:func:`re.sub`. The callable should expect one positional argument
(a regex object) and return a string.
To get the idea:
>>> pd.Series(['foo', 'fuz', np.nan]).str.replace('f', repr)
0 <_sre.SRE_Match object; span=(0, 1), match='f'>oo
1 <_sre.SRE_Match object; span=(0, 1), match='f'>uz
2 NaN
dtype: object
Reverse every lowercase alphabetic word:
>>> repl = lambda m: m.group(0)[::-1]
>>> pd.Series(['foo 123', 'bar baz', np.nan]).str.replace(r'[a-z]+', repl)
0 oof 123
1 rab zab
2 NaN
dtype: object
Using regex groups (extract second group and swap case):
>>> pat = r"(?P<one>\w+) (?P<two>\w+) (?P<three>\w+)"
>>> repl = lambda m: m.group('two').swapcase()
>>> pd.Series(['One Two Three', 'Foo Bar Baz']).str.replace(pat, repl)
0 tWO
1 bAR
dtype: object
Using a compiled regex with flags
>>> import re
>>> regex_pat = re.compile(r'FUZ', flags=re.IGNORECASE)
>>> pd.Series(['foo', 'fuz', np.nan]).str.replace(regex_pat, 'bar')
0 foo
1 bar
2 NaN
dtype: object
"""
# Check whether repl is valid (GH 13438, GH 15055)
if not (is_string_like(repl) or callable(repl)):
raise TypeError("repl must be a string or callable")
is_compiled_re = is_re(pat)
if regex:
if is_compiled_re:
if (case is not None) or (flags != 0):
raise ValueError("case and flags cannot be set"
" when pat is a compiled regex")
else:
# not a compiled regex
# set default case
if case is None:
case = True
# add case flag, if provided
if case is False:
flags |= re.IGNORECASE
if is_compiled_re or len(pat) > 1 or flags or callable(repl):
n = n if n >= 0 else 0
compiled = re.compile(pat, flags=flags)
f = lambda x: compiled.sub(repl=repl, string=x, count=n)
else:
f = lambda x: x.replace(pat, repl, n)
else:
if is_compiled_re:
raise ValueError("Cannot use a compiled regex as replacement "
"pattern with regex=False")
if callable(repl):
raise ValueError("Cannot use a callable replacement when "
"regex=False")
f = lambda x: x.replace(pat, repl, n)
return _na_map(f, arr) |
Duplicate each string in the Series or Index.
Parameters
----------
repeats : int or sequence of int
Same value for all (int) or different value per (sequence).
Returns
-------
Series or Index of object
Series or Index of repeated string objects specified by
input parameter repeats.
Examples
--------
>>> s = pd.Series(['a', 'b', 'c'])
>>> s
0 a
1 b
2 c
dtype: object
Single int repeats string in Series
>>> s.str.repeat(repeats=2)
0 aa
1 bb
2 cc
dtype: object
Sequence of int repeats corresponding string in Series
>>> s.str.repeat(repeats=[1, 2, 3])
0 a
1 bb
2 ccc
dtype: object | def str_repeat(arr, repeats):
"""
Duplicate each string in the Series or Index.
Parameters
----------
repeats : int or sequence of int
Same value for all (int) or different value per (sequence).
Returns
-------
Series or Index of object
Series or Index of repeated string objects specified by
input parameter repeats.
Examples
--------
>>> s = pd.Series(['a', 'b', 'c'])
>>> s
0 a
1 b
2 c
dtype: object
Single int repeats string in Series
>>> s.str.repeat(repeats=2)
0 aa
1 bb
2 cc
dtype: object
Sequence of int repeats corresponding string in Series
>>> s.str.repeat(repeats=[1, 2, 3])
0 a
1 bb
2 ccc
dtype: object
"""
if is_scalar(repeats):
def scalar_rep(x):
try:
return bytes.__mul__(x, repeats)
except TypeError:
return str.__mul__(x, repeats)
return _na_map(scalar_rep, arr)
else:
def rep(x, r):
try:
return bytes.__mul__(x, r)
except TypeError:
return str.__mul__(x, r)
repeats = np.asarray(repeats, dtype=object)
result = libops.vec_binop(com.values_from_object(arr), repeats, rep)
return result |
Determine if each string matches a regular expression.
Parameters
----------
pat : str
Character sequence or regular expression.
case : bool, default True
If True, case sensitive.
flags : int, default 0 (no flags)
re module flags, e.g. re.IGNORECASE.
na : default NaN
Fill value for missing values.
Returns
-------
Series/array of boolean values
See Also
--------
contains : Analogous, but less strict, relying on re.search instead of
re.match.
extract : Extract matched groups. | def str_match(arr, pat, case=True, flags=0, na=np.nan):
"""
Determine if each string matches a regular expression.
Parameters
----------
pat : str
Character sequence or regular expression.
case : bool, default True
If True, case sensitive.
flags : int, default 0 (no flags)
re module flags, e.g. re.IGNORECASE.
na : default NaN
Fill value for missing values.
Returns
-------
Series/array of boolean values
See Also
--------
contains : Analogous, but less strict, relying on re.search instead of
re.match.
extract : Extract matched groups.
"""
if not case:
flags |= re.IGNORECASE
regex = re.compile(pat, flags=flags)
dtype = bool
f = lambda x: bool(regex.match(x))
return _na_map(f, arr, na, dtype=dtype) |
Used in both extract_noexpand and extract_frame | def _groups_or_na_fun(regex):
"""Used in both extract_noexpand and extract_frame"""
if regex.groups == 0:
raise ValueError("pattern contains no capture groups")
empty_row = [np.nan] * regex.groups
def f(x):
if not isinstance(x, str):
return empty_row
m = regex.search(x)
if m:
return [np.nan if item is None else item for item in m.groups()]
else:
return empty_row
return f |
Find groups in each string in the Series using passed regular
expression. This function is called from
str_extract(expand=False), and can return Series, DataFrame, or
Index. | def _str_extract_noexpand(arr, pat, flags=0):
"""
Find groups in each string in the Series using passed regular
expression. This function is called from
str_extract(expand=False), and can return Series, DataFrame, or
Index.
"""
from pandas import DataFrame, Index
regex = re.compile(pat, flags=flags)
groups_or_na = _groups_or_na_fun(regex)
if regex.groups == 1:
result = np.array([groups_or_na(val)[0] for val in arr], dtype=object)
name = _get_single_group_name(regex)
else:
if isinstance(arr, Index):
raise ValueError("only one regex group is supported with Index")
name = None
names = dict(zip(regex.groupindex.values(), regex.groupindex.keys()))
columns = [names.get(1 + i, i) for i in range(regex.groups)]
if arr.empty:
result = DataFrame(columns=columns, dtype=object)
else:
result = DataFrame(
[groups_or_na(val) for val in arr],
columns=columns,
index=arr.index,
dtype=object)
return result, name |
For each subject string in the Series, extract groups from the
first match of regular expression pat. This function is called from
str_extract(expand=True), and always returns a DataFrame. | def _str_extract_frame(arr, pat, flags=0):
"""
For each subject string in the Series, extract groups from the
first match of regular expression pat. This function is called from
str_extract(expand=True), and always returns a DataFrame.
"""
from pandas import DataFrame
regex = re.compile(pat, flags=flags)
groups_or_na = _groups_or_na_fun(regex)
names = dict(zip(regex.groupindex.values(), regex.groupindex.keys()))
columns = [names.get(1 + i, i) for i in range(regex.groups)]
if len(arr) == 0:
return DataFrame(columns=columns, dtype=object)
try:
result_index = arr.index
except AttributeError:
result_index = None
return DataFrame(
[groups_or_na(val) for val in arr],
columns=columns,
index=result_index,
dtype=object) |
r"""
Extract capture groups in the regex `pat` as columns in a DataFrame.
For each subject string in the Series, extract groups from the
first match of regular expression `pat`.
Parameters
----------
pat : str
Regular expression pattern with capturing groups.
flags : int, default 0 (no flags)
Flags from the ``re`` module, e.g. ``re.IGNORECASE``, that
modify regular expression matching for things like case,
spaces, etc. For more details, see :mod:`re`.
expand : bool, default True
If True, return DataFrame with one column per capture group.
If False, return a Series/Index if there is one capture group
or DataFrame if there are multiple capture groups.
.. versionadded:: 0.18.0
Returns
-------
DataFrame or Series or Index
A DataFrame with one row for each subject string, and one
column for each group. Any capture group names in regular
expression pat will be used for column names; otherwise
capture group numbers will be used. The dtype of each result
column is always object, even when no match is found. If
``expand=False`` and pat has only one capture group, then
return a Series (if subject is a Series) or Index (if subject
is an Index).
See Also
--------
extractall : Returns all matches (not just the first match).
Examples
--------
A pattern with two groups will return a DataFrame with two columns.
Non-matches will be NaN.
>>> s = pd.Series(['a1', 'b2', 'c3'])
>>> s.str.extract(r'([ab])(\d)')
0 1
0 a 1
1 b 2
2 NaN NaN
A pattern may contain optional groups.
>>> s.str.extract(r'([ab])?(\d)')
0 1
0 a 1
1 b 2
2 NaN 3
Named groups will become column names in the result.
>>> s.str.extract(r'(?P<letter>[ab])(?P<digit>\d)')
letter digit
0 a 1
1 b 2
2 NaN NaN
A pattern with one group will return a DataFrame with one column
if expand=True.
>>> s.str.extract(r'[ab](\d)', expand=True)
0
0 1
1 2
2 NaN
A pattern with one group will return a Series if expand=False.
>>> s.str.extract(r'[ab](\d)', expand=False)
0 1
1 2
2 NaN
dtype: object | def str_extract(arr, pat, flags=0, expand=True):
r"""
Extract capture groups in the regex `pat` as columns in a DataFrame.
For each subject string in the Series, extract groups from the
first match of regular expression `pat`.
Parameters
----------
pat : str
Regular expression pattern with capturing groups.
flags : int, default 0 (no flags)
Flags from the ``re`` module, e.g. ``re.IGNORECASE``, that
modify regular expression matching for things like case,
spaces, etc. For more details, see :mod:`re`.
expand : bool, default True
If True, return DataFrame with one column per capture group.
If False, return a Series/Index if there is one capture group
or DataFrame if there are multiple capture groups.
.. versionadded:: 0.18.0
Returns
-------
DataFrame or Series or Index
A DataFrame with one row for each subject string, and one
column for each group. Any capture group names in regular
expression pat will be used for column names; otherwise
capture group numbers will be used. The dtype of each result
column is always object, even when no match is found. If
``expand=False`` and pat has only one capture group, then
return a Series (if subject is a Series) or Index (if subject
is an Index).
See Also
--------
extractall : Returns all matches (not just the first match).
Examples
--------
A pattern with two groups will return a DataFrame with two columns.
Non-matches will be NaN.
>>> s = pd.Series(['a1', 'b2', 'c3'])
>>> s.str.extract(r'([ab])(\d)')
0 1
0 a 1
1 b 2
2 NaN NaN
A pattern may contain optional groups.
>>> s.str.extract(r'([ab])?(\d)')
0 1
0 a 1
1 b 2
2 NaN 3
Named groups will become column names in the result.
>>> s.str.extract(r'(?P<letter>[ab])(?P<digit>\d)')
letter digit
0 a 1
1 b 2
2 NaN NaN
A pattern with one group will return a DataFrame with one column
if expand=True.
>>> s.str.extract(r'[ab](\d)', expand=True)
0
0 1
1 2
2 NaN
A pattern with one group will return a Series if expand=False.
>>> s.str.extract(r'[ab](\d)', expand=False)
0 1
1 2
2 NaN
dtype: object
"""
if not isinstance(expand, bool):
raise ValueError("expand must be True or False")
if expand:
return _str_extract_frame(arr._orig, pat, flags=flags)
else:
result, name = _str_extract_noexpand(arr._parent, pat, flags=flags)
return arr._wrap_result(result, name=name, expand=expand) |
r"""
For each subject string in the Series, extract groups from all
matches of regular expression pat. When each subject string in the
Series has exactly one match, extractall(pat).xs(0, level='match')
is the same as extract(pat).
.. versionadded:: 0.18.0
Parameters
----------
pat : str
Regular expression pattern with capturing groups.
flags : int, default 0 (no flags)
A ``re`` module flag, for example ``re.IGNORECASE``. These allow
to modify regular expression matching for things like case, spaces,
etc. Multiple flags can be combined with the bitwise OR operator,
for example ``re.IGNORECASE | re.MULTILINE``.
Returns
-------
DataFrame
A ``DataFrame`` with one row for each match, and one column for each
group. Its rows have a ``MultiIndex`` with first levels that come from
the subject ``Series``. The last level is named 'match' and indexes the
matches in each item of the ``Series``. Any capture group names in
regular expression pat will be used for column names; otherwise capture
group numbers will be used.
See Also
--------
extract : Returns first match only (not all matches).
Examples
--------
A pattern with one group will return a DataFrame with one column.
Indices with no matches will not appear in the result.
>>> s = pd.Series(["a1a2", "b1", "c1"], index=["A", "B", "C"])
>>> s.str.extractall(r"[ab](\d)")
0
match
A 0 1
1 2
B 0 1
Capture group names are used for column names of the result.
>>> s.str.extractall(r"[ab](?P<digit>\d)")
digit
match
A 0 1
1 2
B 0 1
A pattern with two groups will return a DataFrame with two columns.
>>> s.str.extractall(r"(?P<letter>[ab])(?P<digit>\d)")
letter digit
match
A 0 a 1
1 a 2
B 0 b 1
Optional groups that do not match are NaN in the result.
>>> s.str.extractall(r"(?P<letter>[ab])?(?P<digit>\d)")
letter digit
match
A 0 a 1
1 a 2
B 0 b 1
C 0 NaN 1 | def str_extractall(arr, pat, flags=0):
r"""
For each subject string in the Series, extract groups from all
matches of regular expression pat. When each subject string in the
Series has exactly one match, extractall(pat).xs(0, level='match')
is the same as extract(pat).
.. versionadded:: 0.18.0
Parameters
----------
pat : str
Regular expression pattern with capturing groups.
flags : int, default 0 (no flags)
A ``re`` module flag, for example ``re.IGNORECASE``. These allow
to modify regular expression matching for things like case, spaces,
etc. Multiple flags can be combined with the bitwise OR operator,
for example ``re.IGNORECASE | re.MULTILINE``.
Returns
-------
DataFrame
A ``DataFrame`` with one row for each match, and one column for each
group. Its rows have a ``MultiIndex`` with first levels that come from
the subject ``Series``. The last level is named 'match' and indexes the
matches in each item of the ``Series``. Any capture group names in
regular expression pat will be used for column names; otherwise capture
group numbers will be used.
See Also
--------
extract : Returns first match only (not all matches).
Examples
--------
A pattern with one group will return a DataFrame with one column.
Indices with no matches will not appear in the result.
>>> s = pd.Series(["a1a2", "b1", "c1"], index=["A", "B", "C"])
>>> s.str.extractall(r"[ab](\d)")
0
match
A 0 1
1 2
B 0 1
Capture group names are used for column names of the result.
>>> s.str.extractall(r"[ab](?P<digit>\d)")
digit
match
A 0 1
1 2
B 0 1
A pattern with two groups will return a DataFrame with two columns.
>>> s.str.extractall(r"(?P<letter>[ab])(?P<digit>\d)")
letter digit
match
A 0 a 1
1 a 2
B 0 b 1
Optional groups that do not match are NaN in the result.
>>> s.str.extractall(r"(?P<letter>[ab])?(?P<digit>\d)")
letter digit
match
A 0 a 1
1 a 2
B 0 b 1
C 0 NaN 1
"""
regex = re.compile(pat, flags=flags)
# the regex must contain capture groups.
if regex.groups == 0:
raise ValueError("pattern contains no capture groups")
if isinstance(arr, ABCIndexClass):
arr = arr.to_series().reset_index(drop=True)
names = dict(zip(regex.groupindex.values(), regex.groupindex.keys()))
columns = [names.get(1 + i, i) for i in range(regex.groups)]
match_list = []
index_list = []
is_mi = arr.index.nlevels > 1
for subject_key, subject in arr.iteritems():
if isinstance(subject, str):
if not is_mi:
subject_key = (subject_key, )
for match_i, match_tuple in enumerate(regex.findall(subject)):
if isinstance(match_tuple, str):
match_tuple = (match_tuple,)
na_tuple = [np.NaN if group == "" else group
for group in match_tuple]
match_list.append(na_tuple)
result_key = tuple(subject_key + (match_i, ))
index_list.append(result_key)
from pandas import MultiIndex
index = MultiIndex.from_tuples(
index_list, names=arr.index.names + ["match"])
result = arr._constructor_expanddim(match_list, index=index,
columns=columns)
return result |
Split each string in the Series by sep and return a DataFrame
of dummy/indicator variables.
Parameters
----------
sep : str, default "|"
String to split on.
Returns
-------
DataFrame
Dummy variables corresponding to values of the Series.
See Also
--------
get_dummies : Convert categorical variable into dummy/indicator
variables.
Examples
--------
>>> pd.Series(['a|b', 'a', 'a|c']).str.get_dummies()
a b c
0 1 1 0
1 1 0 0
2 1 0 1
>>> pd.Series(['a|b', np.nan, 'a|c']).str.get_dummies()
a b c
0 1 1 0
1 0 0 0
2 1 0 1 | def str_get_dummies(arr, sep='|'):
"""
Split each string in the Series by sep and return a DataFrame
of dummy/indicator variables.
Parameters
----------
sep : str, default "|"
String to split on.
Returns
-------
DataFrame
Dummy variables corresponding to values of the Series.
See Also
--------
get_dummies : Convert categorical variable into dummy/indicator
variables.
Examples
--------
>>> pd.Series(['a|b', 'a', 'a|c']).str.get_dummies()
a b c
0 1 1 0
1 1 0 0
2 1 0 1
>>> pd.Series(['a|b', np.nan, 'a|c']).str.get_dummies()
a b c
0 1 1 0
1 0 0 0
2 1 0 1
"""
arr = arr.fillna('')
try:
arr = sep + arr + sep
except TypeError:
arr = sep + arr.astype(str) + sep
tags = set()
for ts in arr.str.split(sep):
tags.update(ts)
tags = sorted(tags - {""})
dummies = np.empty((len(arr), len(tags)), dtype=np.int64)
for i, t in enumerate(tags):
pat = sep + t + sep
dummies[:, i] = lib.map_infer(arr.values, lambda x: pat in x)
return dummies, tags |
Find all occurrences of pattern or regular expression in the Series/Index.
Equivalent to applying :func:`re.findall` to all the elements in the
Series/Index.
Parameters
----------
pat : str
Pattern or regular expression.
flags : int, default 0
Flags from ``re`` module, e.g. `re.IGNORECASE` (default is 0, which
means no flags).
Returns
-------
Series/Index of lists of strings
All non-overlapping matches of pattern or regular expression in each
string of this Series/Index.
See Also
--------
count : Count occurrences of pattern or regular expression in each string
of the Series/Index.
extractall : For each string in the Series, extract groups from all matches
of regular expression and return a DataFrame with one row for each
match and one column for each group.
re.findall : The equivalent ``re`` function to all non-overlapping matches
of pattern or regular expression in string, as a list of strings.
Examples
--------
>>> s = pd.Series(['Lion', 'Monkey', 'Rabbit'])
The search for the pattern 'Monkey' returns one match:
>>> s.str.findall('Monkey')
0 []
1 [Monkey]
2 []
dtype: object
On the other hand, the search for the pattern 'MONKEY' doesn't return any
match:
>>> s.str.findall('MONKEY')
0 []
1 []
2 []
dtype: object
Flags can be added to the pattern or regular expression. For instance,
to find the pattern 'MONKEY' ignoring the case:
>>> import re
>>> s.str.findall('MONKEY', flags=re.IGNORECASE)
0 []
1 [Monkey]
2 []
dtype: object
When the pattern matches more than one string in the Series, all matches
are returned:
>>> s.str.findall('on')
0 [on]
1 [on]
2 []
dtype: object
Regular expressions are supported too. For instance, the search for all the
strings ending with the word 'on' is shown next:
>>> s.str.findall('on$')
0 [on]
1 []
2 []
dtype: object
If the pattern is found more than once in the same string, then a list of
multiple strings is returned:
>>> s.str.findall('b')
0 []
1 []
2 [b, b]
dtype: object | def str_findall(arr, pat, flags=0):
"""
Find all occurrences of pattern or regular expression in the Series/Index.
Equivalent to applying :func:`re.findall` to all the elements in the
Series/Index.
Parameters
----------
pat : str
Pattern or regular expression.
flags : int, default 0
Flags from ``re`` module, e.g. `re.IGNORECASE` (default is 0, which
means no flags).
Returns
-------
Series/Index of lists of strings
All non-overlapping matches of pattern or regular expression in each
string of this Series/Index.
See Also
--------
count : Count occurrences of pattern or regular expression in each string
of the Series/Index.
extractall : For each string in the Series, extract groups from all matches
of regular expression and return a DataFrame with one row for each
match and one column for each group.
re.findall : The equivalent ``re`` function to all non-overlapping matches
of pattern or regular expression in string, as a list of strings.
Examples
--------
>>> s = pd.Series(['Lion', 'Monkey', 'Rabbit'])
The search for the pattern 'Monkey' returns one match:
>>> s.str.findall('Monkey')
0 []
1 [Monkey]
2 []
dtype: object
On the other hand, the search for the pattern 'MONKEY' doesn't return any
match:
>>> s.str.findall('MONKEY')
0 []
1 []
2 []
dtype: object
Flags can be added to the pattern or regular expression. For instance,
to find the pattern 'MONKEY' ignoring the case:
>>> import re
>>> s.str.findall('MONKEY', flags=re.IGNORECASE)
0 []
1 [Monkey]
2 []
dtype: object
When the pattern matches more than one string in the Series, all matches
are returned:
>>> s.str.findall('on')
0 [on]
1 [on]
2 []
dtype: object
Regular expressions are supported too. For instance, the search for all the
strings ending with the word 'on' is shown next:
>>> s.str.findall('on$')
0 [on]
1 []
2 []
dtype: object
If the pattern is found more than once in the same string, then a list of
multiple strings is returned:
>>> s.str.findall('b')
0 []
1 []
2 [b, b]
dtype: object
"""
regex = re.compile(pat, flags=flags)
return _na_map(regex.findall, arr) |
Return indexes in each strings in the Series/Index where the
substring is fully contained between [start:end]. Return -1 on failure.
Parameters
----------
sub : str
Substring being searched.
start : int
Left edge index.
end : int
Right edge index.
side : {'left', 'right'}, default 'left'
Specifies a starting side, equivalent to ``find`` or ``rfind``.
Returns
-------
Series or Index
Indexes where substring is found. | def str_find(arr, sub, start=0, end=None, side='left'):
"""
Return indexes in each strings in the Series/Index where the
substring is fully contained between [start:end]. Return -1 on failure.
Parameters
----------
sub : str
Substring being searched.
start : int
Left edge index.
end : int
Right edge index.
side : {'left', 'right'}, default 'left'
Specifies a starting side, equivalent to ``find`` or ``rfind``.
Returns
-------
Series or Index
Indexes where substring is found.
"""
if not isinstance(sub, str):
msg = 'expected a string object, not {0}'
raise TypeError(msg.format(type(sub).__name__))
if side == 'left':
method = 'find'
elif side == 'right':
method = 'rfind'
else: # pragma: no cover
raise ValueError('Invalid side')
if end is None:
f = lambda x: getattr(x, method)(sub, start)
else:
f = lambda x: getattr(x, method)(sub, start, end)
return _na_map(f, arr, dtype=int) |
Pad strings in the Series/Index up to width.
Parameters
----------
width : int
Minimum width of resulting string; additional characters will be filled
with character defined in `fillchar`.
side : {'left', 'right', 'both'}, default 'left'
Side from which to fill resulting string.
fillchar : str, default ' '
Additional character for filling, default is whitespace.
Returns
-------
Series or Index of object
Returns Series or Index with minimum number of char in object.
See Also
--------
Series.str.rjust : Fills the left side of strings with an arbitrary
character. Equivalent to ``Series.str.pad(side='left')``.
Series.str.ljust : Fills the right side of strings with an arbitrary
character. Equivalent to ``Series.str.pad(side='right')``.
Series.str.center : Fills boths sides of strings with an arbitrary
character. Equivalent to ``Series.str.pad(side='both')``.
Series.str.zfill : Pad strings in the Series/Index by prepending '0'
character. Equivalent to ``Series.str.pad(side='left', fillchar='0')``.
Examples
--------
>>> s = pd.Series(["caribou", "tiger"])
>>> s
0 caribou
1 tiger
dtype: object
>>> s.str.pad(width=10)
0 caribou
1 tiger
dtype: object
>>> s.str.pad(width=10, side='right', fillchar='-')
0 caribou---
1 tiger-----
dtype: object
>>> s.str.pad(width=10, side='both', fillchar='-')
0 -caribou--
1 --tiger---
dtype: object | def str_pad(arr, width, side='left', fillchar=' '):
"""
Pad strings in the Series/Index up to width.
Parameters
----------
width : int
Minimum width of resulting string; additional characters will be filled
with character defined in `fillchar`.
side : {'left', 'right', 'both'}, default 'left'
Side from which to fill resulting string.
fillchar : str, default ' '
Additional character for filling, default is whitespace.
Returns
-------
Series or Index of object
Returns Series or Index with minimum number of char in object.
See Also
--------
Series.str.rjust : Fills the left side of strings with an arbitrary
character. Equivalent to ``Series.str.pad(side='left')``.
Series.str.ljust : Fills the right side of strings with an arbitrary
character. Equivalent to ``Series.str.pad(side='right')``.
Series.str.center : Fills boths sides of strings with an arbitrary
character. Equivalent to ``Series.str.pad(side='both')``.
Series.str.zfill : Pad strings in the Series/Index by prepending '0'
character. Equivalent to ``Series.str.pad(side='left', fillchar='0')``.
Examples
--------
>>> s = pd.Series(["caribou", "tiger"])
>>> s
0 caribou
1 tiger
dtype: object
>>> s.str.pad(width=10)
0 caribou
1 tiger
dtype: object
>>> s.str.pad(width=10, side='right', fillchar='-')
0 caribou---
1 tiger-----
dtype: object
>>> s.str.pad(width=10, side='both', fillchar='-')
0 -caribou--
1 --tiger---
dtype: object
"""
if not isinstance(fillchar, str):
msg = 'fillchar must be a character, not {0}'
raise TypeError(msg.format(type(fillchar).__name__))
if len(fillchar) != 1:
raise TypeError('fillchar must be a character, not str')
if not is_integer(width):
msg = 'width must be of integer type, not {0}'
raise TypeError(msg.format(type(width).__name__))
if side == 'left':
f = lambda x: x.rjust(width, fillchar)
elif side == 'right':
f = lambda x: x.ljust(width, fillchar)
elif side == 'both':
f = lambda x: x.center(width, fillchar)
else: # pragma: no cover
raise ValueError('Invalid side')
return _na_map(f, arr) |
Slice substrings from each element in the Series or Index.
Parameters
----------
start : int, optional
Start position for slice operation.
stop : int, optional
Stop position for slice operation.
step : int, optional
Step size for slice operation.
Returns
-------
Series or Index of object
Series or Index from sliced substring from original string object.
See Also
--------
Series.str.slice_replace : Replace a slice with a string.
Series.str.get : Return element at position.
Equivalent to `Series.str.slice(start=i, stop=i+1)` with `i`
being the position.
Examples
--------
>>> s = pd.Series(["koala", "fox", "chameleon"])
>>> s
0 koala
1 fox
2 chameleon
dtype: object
>>> s.str.slice(start=1)
0 oala
1 ox
2 hameleon
dtype: object
>>> s.str.slice(stop=2)
0 ko
1 fo
2 ch
dtype: object
>>> s.str.slice(step=2)
0 kaa
1 fx
2 caeen
dtype: object
>>> s.str.slice(start=0, stop=5, step=3)
0 kl
1 f
2 cm
dtype: object
Equivalent behaviour to:
>>> s.str[0:5:3]
0 kl
1 f
2 cm
dtype: object | def str_slice(arr, start=None, stop=None, step=None):
"""
Slice substrings from each element in the Series or Index.
Parameters
----------
start : int, optional
Start position for slice operation.
stop : int, optional
Stop position for slice operation.
step : int, optional
Step size for slice operation.
Returns
-------
Series or Index of object
Series or Index from sliced substring from original string object.
See Also
--------
Series.str.slice_replace : Replace a slice with a string.
Series.str.get : Return element at position.
Equivalent to `Series.str.slice(start=i, stop=i+1)` with `i`
being the position.
Examples
--------
>>> s = pd.Series(["koala", "fox", "chameleon"])
>>> s
0 koala
1 fox
2 chameleon
dtype: object
>>> s.str.slice(start=1)
0 oala
1 ox
2 hameleon
dtype: object
>>> s.str.slice(stop=2)
0 ko
1 fo
2 ch
dtype: object
>>> s.str.slice(step=2)
0 kaa
1 fx
2 caeen
dtype: object
>>> s.str.slice(start=0, stop=5, step=3)
0 kl
1 f
2 cm
dtype: object
Equivalent behaviour to:
>>> s.str[0:5:3]
0 kl
1 f
2 cm
dtype: object
"""
obj = slice(start, stop, step)
f = lambda x: x[obj]
return _na_map(f, arr) |
Replace a positional slice of a string with another value.
Parameters
----------
start : int, optional
Left index position to use for the slice. If not specified (None),
the slice is unbounded on the left, i.e. slice from the start
of the string.
stop : int, optional
Right index position to use for the slice. If not specified (None),
the slice is unbounded on the right, i.e. slice until the
end of the string.
repl : str, optional
String for replacement. If not specified (None), the sliced region
is replaced with an empty string.
Returns
-------
Series or Index
Same type as the original object.
See Also
--------
Series.str.slice : Just slicing without replacement.
Examples
--------
>>> s = pd.Series(['a', 'ab', 'abc', 'abdc', 'abcde'])
>>> s
0 a
1 ab
2 abc
3 abdc
4 abcde
dtype: object
Specify just `start`, meaning replace `start` until the end of the
string with `repl`.
>>> s.str.slice_replace(1, repl='X')
0 aX
1 aX
2 aX
3 aX
4 aX
dtype: object
Specify just `stop`, meaning the start of the string to `stop` is replaced
with `repl`, and the rest of the string is included.
>>> s.str.slice_replace(stop=2, repl='X')
0 X
1 X
2 Xc
3 Xdc
4 Xcde
dtype: object
Specify `start` and `stop`, meaning the slice from `start` to `stop` is
replaced with `repl`. Everything before or after `start` and `stop` is
included as is.
>>> s.str.slice_replace(start=1, stop=3, repl='X')
0 aX
1 aX
2 aX
3 aXc
4 aXde
dtype: object | def str_slice_replace(arr, start=None, stop=None, repl=None):
"""
Replace a positional slice of a string with another value.
Parameters
----------
start : int, optional
Left index position to use for the slice. If not specified (None),
the slice is unbounded on the left, i.e. slice from the start
of the string.
stop : int, optional
Right index position to use for the slice. If not specified (None),
the slice is unbounded on the right, i.e. slice until the
end of the string.
repl : str, optional
String for replacement. If not specified (None), the sliced region
is replaced with an empty string.
Returns
-------
Series or Index
Same type as the original object.
See Also
--------
Series.str.slice : Just slicing without replacement.
Examples
--------
>>> s = pd.Series(['a', 'ab', 'abc', 'abdc', 'abcde'])
>>> s
0 a
1 ab
2 abc
3 abdc
4 abcde
dtype: object
Specify just `start`, meaning replace `start` until the end of the
string with `repl`.
>>> s.str.slice_replace(1, repl='X')
0 aX
1 aX
2 aX
3 aX
4 aX
dtype: object
Specify just `stop`, meaning the start of the string to `stop` is replaced
with `repl`, and the rest of the string is included.
>>> s.str.slice_replace(stop=2, repl='X')
0 X
1 X
2 Xc
3 Xdc
4 Xcde
dtype: object
Specify `start` and `stop`, meaning the slice from `start` to `stop` is
replaced with `repl`. Everything before or after `start` and `stop` is
included as is.
>>> s.str.slice_replace(start=1, stop=3, repl='X')
0 aX
1 aX
2 aX
3 aXc
4 aXde
dtype: object
"""
if repl is None:
repl = ''
def f(x):
if x[start:stop] == '':
local_stop = start
else:
local_stop = stop
y = ''
if start is not None:
y += x[:start]
y += repl
if stop is not None:
y += x[local_stop:]
return y
return _na_map(f, arr) |
Strip whitespace (including newlines) from each string in the
Series/Index.
Parameters
----------
to_strip : str or unicode
side : {'left', 'right', 'both'}, default 'both'
Returns
-------
Series or Index | def str_strip(arr, to_strip=None, side='both'):
"""
Strip whitespace (including newlines) from each string in the
Series/Index.
Parameters
----------
to_strip : str or unicode
side : {'left', 'right', 'both'}, default 'both'
Returns
-------
Series or Index
"""
if side == 'both':
f = lambda x: x.strip(to_strip)
elif side == 'left':
f = lambda x: x.lstrip(to_strip)
elif side == 'right':
f = lambda x: x.rstrip(to_strip)
else: # pragma: no cover
raise ValueError('Invalid side')
return _na_map(f, arr) |
r"""
Wrap long strings in the Series/Index to be formatted in
paragraphs with length less than a given width.
This method has the same keyword parameters and defaults as
:class:`textwrap.TextWrapper`.
Parameters
----------
width : int
Maximum line width.
expand_tabs : bool, optional
If True, tab characters will be expanded to spaces (default: True).
replace_whitespace : bool, optional
If True, each whitespace character (as defined by string.whitespace)
remaining after tab expansion will be replaced by a single space
(default: True).
drop_whitespace : bool, optional
If True, whitespace that, after wrapping, happens to end up at the
beginning or end of a line is dropped (default: True).
break_long_words : bool, optional
If True, then words longer than width will be broken in order to ensure
that no lines are longer than width. If it is false, long words will
not be broken, and some lines may be longer than width (default: True).
break_on_hyphens : bool, optional
If True, wrapping will occur preferably on whitespace and right after
hyphens in compound words, as it is customary in English. If false,
only whitespaces will be considered as potentially good places for line
breaks, but you need to set break_long_words to false if you want truly
insecable words (default: True).
Returns
-------
Series or Index
Notes
-----
Internally, this method uses a :class:`textwrap.TextWrapper` instance with
default settings. To achieve behavior matching R's stringr library str_wrap
function, use the arguments:
- expand_tabs = False
- replace_whitespace = True
- drop_whitespace = True
- break_long_words = False
- break_on_hyphens = False
Examples
--------
>>> s = pd.Series(['line to be wrapped', 'another line to be wrapped'])
>>> s.str.wrap(12)
0 line to be\nwrapped
1 another line\nto be\nwrapped
dtype: object | def str_wrap(arr, width, **kwargs):
r"""
Wrap long strings in the Series/Index to be formatted in
paragraphs with length less than a given width.
This method has the same keyword parameters and defaults as
:class:`textwrap.TextWrapper`.
Parameters
----------
width : int
Maximum line width.
expand_tabs : bool, optional
If True, tab characters will be expanded to spaces (default: True).
replace_whitespace : bool, optional
If True, each whitespace character (as defined by string.whitespace)
remaining after tab expansion will be replaced by a single space
(default: True).
drop_whitespace : bool, optional
If True, whitespace that, after wrapping, happens to end up at the
beginning or end of a line is dropped (default: True).
break_long_words : bool, optional
If True, then words longer than width will be broken in order to ensure
that no lines are longer than width. If it is false, long words will
not be broken, and some lines may be longer than width (default: True).
break_on_hyphens : bool, optional
If True, wrapping will occur preferably on whitespace and right after
hyphens in compound words, as it is customary in English. If false,
only whitespaces will be considered as potentially good places for line
breaks, but you need to set break_long_words to false if you want truly
insecable words (default: True).
Returns
-------
Series or Index
Notes
-----
Internally, this method uses a :class:`textwrap.TextWrapper` instance with
default settings. To achieve behavior matching R's stringr library str_wrap
function, use the arguments:
- expand_tabs = False
- replace_whitespace = True
- drop_whitespace = True
- break_long_words = False
- break_on_hyphens = False
Examples
--------
>>> s = pd.Series(['line to be wrapped', 'another line to be wrapped'])
>>> s.str.wrap(12)
0 line to be\nwrapped
1 another line\nto be\nwrapped
dtype: object
"""
kwargs['width'] = width
tw = textwrap.TextWrapper(**kwargs)
return _na_map(lambda s: '\n'.join(tw.wrap(s)), arr) |
Extract element from each component at specified position.
Extract element from lists, tuples, or strings in each element in the
Series/Index.
Parameters
----------
i : int
Position of element to extract.
Returns
-------
Series or Index
Examples
--------
>>> s = pd.Series(["String",
... (1, 2, 3),
... ["a", "b", "c"],
... 123,
... -456,
... {1: "Hello", "2": "World"}])
>>> s
0 String
1 (1, 2, 3)
2 [a, b, c]
3 123
4 -456
5 {1: 'Hello', '2': 'World'}
dtype: object
>>> s.str.get(1)
0 t
1 2
2 b
3 NaN
4 NaN
5 Hello
dtype: object
>>> s.str.get(-1)
0 g
1 3
2 c
3 NaN
4 NaN
5 None
dtype: object | def str_get(arr, i):
"""
Extract element from each component at specified position.
Extract element from lists, tuples, or strings in each element in the
Series/Index.
Parameters
----------
i : int
Position of element to extract.
Returns
-------
Series or Index
Examples
--------
>>> s = pd.Series(["String",
... (1, 2, 3),
... ["a", "b", "c"],
... 123,
... -456,
... {1: "Hello", "2": "World"}])
>>> s
0 String
1 (1, 2, 3)
2 [a, b, c]
3 123
4 -456
5 {1: 'Hello', '2': 'World'}
dtype: object
>>> s.str.get(1)
0 t
1 2
2 b
3 NaN
4 NaN
5 Hello
dtype: object
>>> s.str.get(-1)
0 g
1 3
2 c
3 NaN
4 NaN
5 None
dtype: object
"""
def f(x):
if isinstance(x, dict):
return x.get(i)
elif len(x) > i >= -len(x):
return x[i]
return np.nan
return _na_map(f, arr) |
Decode character string in the Series/Index using indicated encoding.
Equivalent to :meth:`str.decode` in python2 and :meth:`bytes.decode` in
python3.
Parameters
----------
encoding : str
errors : str, optional
Returns
-------
Series or Index | def str_decode(arr, encoding, errors="strict"):
"""
Decode character string in the Series/Index using indicated encoding.
Equivalent to :meth:`str.decode` in python2 and :meth:`bytes.decode` in
python3.
Parameters
----------
encoding : str
errors : str, optional
Returns
-------
Series or Index
"""
if encoding in _cpython_optimized_decoders:
# CPython optimized implementation
f = lambda x: x.decode(encoding, errors)
else:
decoder = codecs.getdecoder(encoding)
f = lambda x: decoder(x, errors)[0]
return _na_map(f, arr) |
Encode character string in the Series/Index using indicated encoding.
Equivalent to :meth:`str.encode`.
Parameters
----------
encoding : str
errors : str, optional
Returns
-------
encoded : Series/Index of objects | def str_encode(arr, encoding, errors="strict"):
"""
Encode character string in the Series/Index using indicated encoding.
Equivalent to :meth:`str.encode`.
Parameters
----------
encoding : str
errors : str, optional
Returns
-------
encoded : Series/Index of objects
"""
if encoding in _cpython_optimized_encoders:
# CPython optimized implementation
f = lambda x: x.encode(encoding, errors)
else:
encoder = codecs.getencoder(encoding)
f = lambda x: encoder(x, errors)[0]
return _na_map(f, arr) |
Copy a docstring from another source function (if present) | def copy(source):
"Copy a docstring from another source function (if present)"
def do_copy(target):
if source.__doc__:
target.__doc__ = source.__doc__
return target
return do_copy |
Auxiliary function for :meth:`str.cat`. Turn potentially mixed input
into a list of Series (elements without an index must match the length
of the calling Series/Index).
Parameters
----------
others : Series, Index, DataFrame, np.ndarray, list-like or list-like
of objects that are Series, Index or np.ndarray (1-dim)
ignore_index : boolean, default False
Determines whether to forcefully align others with index of caller
Returns
-------
tuple : (others transformed into list of Series,
boolean whether FutureWarning should be raised) | def _get_series_list(self, others, ignore_index=False):
"""
Auxiliary function for :meth:`str.cat`. Turn potentially mixed input
into a list of Series (elements without an index must match the length
of the calling Series/Index).
Parameters
----------
others : Series, Index, DataFrame, np.ndarray, list-like or list-like
of objects that are Series, Index or np.ndarray (1-dim)
ignore_index : boolean, default False
Determines whether to forcefully align others with index of caller
Returns
-------
tuple : (others transformed into list of Series,
boolean whether FutureWarning should be raised)
"""
# Once str.cat defaults to alignment, this function can be simplified;
# will not need `ignore_index` and the second boolean output anymore
from pandas import Index, Series, DataFrame
# self._orig is either Series or Index
idx = self._orig if isinstance(self._orig, Index) else self._orig.index
err_msg = ('others must be Series, Index, DataFrame, np.ndarrary or '
'list-like (either containing only strings or containing '
'only objects of type Series/Index/list-like/np.ndarray)')
# Generally speaking, all objects without an index inherit the index
# `idx` of the calling Series/Index - i.e. must have matching length.
# Objects with an index (i.e. Series/Index/DataFrame) keep their own
# index, *unless* ignore_index is set to True.
if isinstance(others, Series):
warn = not others.index.equals(idx)
# only reconstruct Series when absolutely necessary
los = [Series(others.values, index=idx)
if ignore_index and warn else others]
return (los, warn)
elif isinstance(others, Index):
warn = not others.equals(idx)
los = [Series(others.values,
index=(idx if ignore_index else others))]
return (los, warn)
elif isinstance(others, DataFrame):
warn = not others.index.equals(idx)
if ignore_index and warn:
# without copy, this could change "others"
# that was passed to str.cat
others = others.copy()
others.index = idx
return ([others[x] for x in others], warn)
elif isinstance(others, np.ndarray) and others.ndim == 2:
others = DataFrame(others, index=idx)
return ([others[x] for x in others], False)
elif is_list_like(others, allow_sets=False):
others = list(others) # ensure iterators do not get read twice etc
# in case of list-like `others`, all elements must be
# either one-dimensional list-likes or scalars
if all(is_list_like(x, allow_sets=False) for x in others):
los = []
join_warn = False
depr_warn = False
# iterate through list and append list of series for each
# element (which we check to be one-dimensional and non-nested)
while others:
nxt = others.pop(0) # nxt is guaranteed list-like by above
# GH 21950 - DeprecationWarning
# only allowing Series/Index/np.ndarray[1-dim] will greatly
# simply this function post-deprecation.
if not (isinstance(nxt, (Series, Index)) or
(isinstance(nxt, np.ndarray) and nxt.ndim == 1)):
depr_warn = True
if not isinstance(nxt, (DataFrame, Series,
Index, np.ndarray)):
# safety for non-persistent list-likes (e.g. iterators)
# do not map indexed/typed objects; info needed below
nxt = list(nxt)
# known types for which we can avoid deep inspection
no_deep = ((isinstance(nxt, np.ndarray) and nxt.ndim == 1)
or isinstance(nxt, (Series, Index)))
# nested list-likes are forbidden:
# -> elements of nxt must not be list-like
is_legal = ((no_deep and nxt.dtype == object)
or all(not is_list_like(x) for x in nxt))
# DataFrame is false positive of is_legal
# because "x in df" returns column names
if not is_legal or isinstance(nxt, DataFrame):
raise TypeError(err_msg)
nxt, wnx = self._get_series_list(nxt,
ignore_index=ignore_index)
los = los + nxt
join_warn = join_warn or wnx
if depr_warn:
warnings.warn('list-likes other than Series, Index, or '
'np.ndarray WITHIN another list-like are '
'deprecated and will be removed in a future '
'version.', FutureWarning, stacklevel=3)
return (los, join_warn)
elif all(not is_list_like(x) for x in others):
return ([Series(others, index=idx)], False)
raise TypeError(err_msg) |
Concatenate strings in the Series/Index with given separator.
If `others` is specified, this function concatenates the Series/Index
and elements of `others` element-wise.
If `others` is not passed, then all values in the Series/Index are
concatenated into a single string with a given `sep`.
Parameters
----------
others : Series, Index, DataFrame, np.ndarrary or list-like
Series, Index, DataFrame, np.ndarray (one- or two-dimensional) and
other list-likes of strings must have the same length as the
calling Series/Index, with the exception of indexed objects (i.e.
Series/Index/DataFrame) if `join` is not None.
If others is a list-like that contains a combination of Series,
Index or np.ndarray (1-dim), then all elements will be unpacked and
must satisfy the above criteria individually.
If others is None, the method returns the concatenation of all
strings in the calling Series/Index.
sep : str, default ''
The separator between the different elements/columns. By default
the empty string `''` is used.
na_rep : str or None, default None
Representation that is inserted for all missing values:
- If `na_rep` is None, and `others` is None, missing values in the
Series/Index are omitted from the result.
- If `na_rep` is None, and `others` is not None, a row containing a
missing value in any of the columns (before concatenation) will
have a missing value in the result.
join : {'left', 'right', 'outer', 'inner'}, default None
Determines the join-style between the calling Series/Index and any
Series/Index/DataFrame in `others` (objects without an index need
to match the length of the calling Series/Index). If None,
alignment is disabled, but this option will be removed in a future
version of pandas and replaced with a default of `'left'`. To
disable alignment, use `.values` on any Series/Index/DataFrame in
`others`.
.. versionadded:: 0.23.0
Returns
-------
str, Series or Index
If `others` is None, `str` is returned, otherwise a `Series/Index`
(same type as caller) of objects is returned.
See Also
--------
split : Split each string in the Series/Index.
join : Join lists contained as elements in the Series/Index.
Examples
--------
When not passing `others`, all values are concatenated into a single
string:
>>> s = pd.Series(['a', 'b', np.nan, 'd'])
>>> s.str.cat(sep=' ')
'a b d'
By default, NA values in the Series are ignored. Using `na_rep`, they
can be given a representation:
>>> s.str.cat(sep=' ', na_rep='?')
'a b ? d'
If `others` is specified, corresponding values are concatenated with
the separator. Result will be a Series of strings.
>>> s.str.cat(['A', 'B', 'C', 'D'], sep=',')
0 a,A
1 b,B
2 NaN
3 d,D
dtype: object
Missing values will remain missing in the result, but can again be
represented using `na_rep`
>>> s.str.cat(['A', 'B', 'C', 'D'], sep=',', na_rep='-')
0 a,A
1 b,B
2 -,C
3 d,D
dtype: object
If `sep` is not specified, the values are concatenated without
separation.
>>> s.str.cat(['A', 'B', 'C', 'D'], na_rep='-')
0 aA
1 bB
2 -C
3 dD
dtype: object
Series with different indexes can be aligned before concatenation. The
`join`-keyword works as in other methods.
>>> t = pd.Series(['d', 'a', 'e', 'c'], index=[3, 0, 4, 2])
>>> s.str.cat(t, join='left', na_rep='-')
0 aa
1 b-
2 -c
3 dd
dtype: object
>>>
>>> s.str.cat(t, join='outer', na_rep='-')
0 aa
1 b-
2 -c
3 dd
4 -e
dtype: object
>>>
>>> s.str.cat(t, join='inner', na_rep='-')
0 aa
2 -c
3 dd
dtype: object
>>>
>>> s.str.cat(t, join='right', na_rep='-')
3 dd
0 aa
4 -e
2 -c
dtype: object
For more examples, see :ref:`here <text.concatenate>`. | def cat(self, others=None, sep=None, na_rep=None, join=None):
"""
Concatenate strings in the Series/Index with given separator.
If `others` is specified, this function concatenates the Series/Index
and elements of `others` element-wise.
If `others` is not passed, then all values in the Series/Index are
concatenated into a single string with a given `sep`.
Parameters
----------
others : Series, Index, DataFrame, np.ndarrary or list-like
Series, Index, DataFrame, np.ndarray (one- or two-dimensional) and
other list-likes of strings must have the same length as the
calling Series/Index, with the exception of indexed objects (i.e.
Series/Index/DataFrame) if `join` is not None.
If others is a list-like that contains a combination of Series,
Index or np.ndarray (1-dim), then all elements will be unpacked and
must satisfy the above criteria individually.
If others is None, the method returns the concatenation of all
strings in the calling Series/Index.
sep : str, default ''
The separator between the different elements/columns. By default
the empty string `''` is used.
na_rep : str or None, default None
Representation that is inserted for all missing values:
- If `na_rep` is None, and `others` is None, missing values in the
Series/Index are omitted from the result.
- If `na_rep` is None, and `others` is not None, a row containing a
missing value in any of the columns (before concatenation) will
have a missing value in the result.
join : {'left', 'right', 'outer', 'inner'}, default None
Determines the join-style between the calling Series/Index and any
Series/Index/DataFrame in `others` (objects without an index need
to match the length of the calling Series/Index). If None,
alignment is disabled, but this option will be removed in a future
version of pandas and replaced with a default of `'left'`. To
disable alignment, use `.values` on any Series/Index/DataFrame in
`others`.
.. versionadded:: 0.23.0
Returns
-------
str, Series or Index
If `others` is None, `str` is returned, otherwise a `Series/Index`
(same type as caller) of objects is returned.
See Also
--------
split : Split each string in the Series/Index.
join : Join lists contained as elements in the Series/Index.
Examples
--------
When not passing `others`, all values are concatenated into a single
string:
>>> s = pd.Series(['a', 'b', np.nan, 'd'])
>>> s.str.cat(sep=' ')
'a b d'
By default, NA values in the Series are ignored. Using `na_rep`, they
can be given a representation:
>>> s.str.cat(sep=' ', na_rep='?')
'a b ? d'
If `others` is specified, corresponding values are concatenated with
the separator. Result will be a Series of strings.
>>> s.str.cat(['A', 'B', 'C', 'D'], sep=',')
0 a,A
1 b,B
2 NaN
3 d,D
dtype: object
Missing values will remain missing in the result, but can again be
represented using `na_rep`
>>> s.str.cat(['A', 'B', 'C', 'D'], sep=',', na_rep='-')
0 a,A
1 b,B
2 -,C
3 d,D
dtype: object
If `sep` is not specified, the values are concatenated without
separation.
>>> s.str.cat(['A', 'B', 'C', 'D'], na_rep='-')
0 aA
1 bB
2 -C
3 dD
dtype: object
Series with different indexes can be aligned before concatenation. The
`join`-keyword works as in other methods.
>>> t = pd.Series(['d', 'a', 'e', 'c'], index=[3, 0, 4, 2])
>>> s.str.cat(t, join='left', na_rep='-')
0 aa
1 b-
2 -c
3 dd
dtype: object
>>>
>>> s.str.cat(t, join='outer', na_rep='-')
0 aa
1 b-
2 -c
3 dd
4 -e
dtype: object
>>>
>>> s.str.cat(t, join='inner', na_rep='-')
0 aa
2 -c
3 dd
dtype: object
>>>
>>> s.str.cat(t, join='right', na_rep='-')
3 dd
0 aa
4 -e
2 -c
dtype: object
For more examples, see :ref:`here <text.concatenate>`.
"""
from pandas import Index, Series, concat
if isinstance(others, str):
raise ValueError("Did you mean to supply a `sep` keyword?")
if sep is None:
sep = ''
if isinstance(self._orig, Index):
data = Series(self._orig, index=self._orig)
else: # Series
data = self._orig
# concatenate Series/Index with itself if no "others"
if others is None:
data = ensure_object(data)
na_mask = isna(data)
if na_rep is None and na_mask.any():
data = data[~na_mask]
elif na_rep is not None and na_mask.any():
data = np.where(na_mask, na_rep, data)
return sep.join(data)
try:
# turn anything in "others" into lists of Series
others, warn = self._get_series_list(others,
ignore_index=(join is None))
except ValueError: # do not catch TypeError raised by _get_series_list
if join is None:
raise ValueError('All arrays must be same length, except '
'those having an index if `join` is not None')
else:
raise ValueError('If `others` contains arrays or lists (or '
'other list-likes without an index), these '
'must all be of the same length as the '
'calling Series/Index.')
if join is None and warn:
warnings.warn("A future version of pandas will perform index "
"alignment when `others` is a Series/Index/"
"DataFrame (or a list-like containing one). To "
"disable alignment (the behavior before v.0.23) and "
"silence this warning, use `.values` on any Series/"
"Index/DataFrame in `others`. To enable alignment "
"and silence this warning, pass `join='left'|"
"'outer'|'inner'|'right'`. The future default will "
"be `join='left'`.", FutureWarning, stacklevel=2)
# if join is None, _get_series_list already force-aligned indexes
join = 'left' if join is None else join
# align if required
if any(not data.index.equals(x.index) for x in others):
# Need to add keys for uniqueness in case of duplicate columns
others = concat(others, axis=1,
join=(join if join == 'inner' else 'outer'),
keys=range(len(others)), sort=False, copy=False)
data, others = data.align(others, join=join)
others = [others[x] for x in others] # again list of Series
all_cols = [ensure_object(x) for x in [data] + others]
na_masks = np.array([isna(x) for x in all_cols])
union_mask = np.logical_or.reduce(na_masks, axis=0)
if na_rep is None and union_mask.any():
# no na_rep means NaNs for all rows where any column has a NaN
# only necessary if there are actually any NaNs
result = np.empty(len(data), dtype=object)
np.putmask(result, union_mask, np.nan)
not_masked = ~union_mask
result[not_masked] = cat_core([x[not_masked] for x in all_cols],
sep)
elif na_rep is not None and union_mask.any():
# fill NaNs with na_rep in case there are actually any NaNs
all_cols = [np.where(nm, na_rep, col)
for nm, col in zip(na_masks, all_cols)]
result = cat_core(all_cols, sep)
else:
# no NaNs - can just concatenate
result = cat_core(all_cols, sep)
if isinstance(self._orig, Index):
# add dtype for case that result is all-NA
result = Index(result, dtype=object, name=self._orig.name)
else: # Series
result = Series(result, dtype=object, index=data.index,
name=self._orig.name)
return result |
Pad strings in the Series/Index by prepending '0' characters.
Strings in the Series/Index are padded with '0' characters on the
left of the string to reach a total string length `width`. Strings
in the Series/Index with length greater or equal to `width` are
unchanged.
Parameters
----------
width : int
Minimum length of resulting string; strings with length less
than `width` be prepended with '0' characters.
Returns
-------
Series/Index of objects
See Also
--------
Series.str.rjust : Fills the left side of strings with an arbitrary
character.
Series.str.ljust : Fills the right side of strings with an arbitrary
character.
Series.str.pad : Fills the specified sides of strings with an arbitrary
character.
Series.str.center : Fills boths sides of strings with an arbitrary
character.
Notes
-----
Differs from :meth:`str.zfill` which has special handling
for '+'/'-' in the string.
Examples
--------
>>> s = pd.Series(['-1', '1', '1000', 10, np.nan])
>>> s
0 -1
1 1
2 1000
3 10
4 NaN
dtype: object
Note that ``10`` and ``NaN`` are not strings, therefore they are
converted to ``NaN``. The minus sign in ``'-1'`` is treated as a
regular character and the zero is added to the left of it
(:meth:`str.zfill` would have moved it to the left). ``1000``
remains unchanged as it is longer than `width`.
>>> s.str.zfill(3)
0 0-1
1 001
2 1000
3 NaN
4 NaN
dtype: object | def zfill(self, width):
"""
Pad strings in the Series/Index by prepending '0' characters.
Strings in the Series/Index are padded with '0' characters on the
left of the string to reach a total string length `width`. Strings
in the Series/Index with length greater or equal to `width` are
unchanged.
Parameters
----------
width : int
Minimum length of resulting string; strings with length less
than `width` be prepended with '0' characters.
Returns
-------
Series/Index of objects
See Also
--------
Series.str.rjust : Fills the left side of strings with an arbitrary
character.
Series.str.ljust : Fills the right side of strings with an arbitrary
character.
Series.str.pad : Fills the specified sides of strings with an arbitrary
character.
Series.str.center : Fills boths sides of strings with an arbitrary
character.
Notes
-----
Differs from :meth:`str.zfill` which has special handling
for '+'/'-' in the string.
Examples
--------
>>> s = pd.Series(['-1', '1', '1000', 10, np.nan])
>>> s
0 -1
1 1
2 1000
3 10
4 NaN
dtype: object
Note that ``10`` and ``NaN`` are not strings, therefore they are
converted to ``NaN``. The minus sign in ``'-1'`` is treated as a
regular character and the zero is added to the left of it
(:meth:`str.zfill` would have moved it to the left). ``1000``
remains unchanged as it is longer than `width`.
>>> s.str.zfill(3)
0 0-1
1 001
2 1000
3 NaN
4 NaN
dtype: object
"""
result = str_pad(self._parent, width, side='left', fillchar='0')
return self._wrap_result(result) |
Return the Unicode normal form for the strings in the Series/Index.
For more information on the forms, see the
:func:`unicodedata.normalize`.
Parameters
----------
form : {'NFC', 'NFKC', 'NFD', 'NFKD'}
Unicode form
Returns
-------
normalized : Series/Index of objects | def normalize(self, form):
"""
Return the Unicode normal form for the strings in the Series/Index.
For more information on the forms, see the
:func:`unicodedata.normalize`.
Parameters
----------
form : {'NFC', 'NFKC', 'NFD', 'NFKD'}
Unicode form
Returns
-------
normalized : Series/Index of objects
"""
import unicodedata
f = lambda x: unicodedata.normalize(form, x)
result = _na_map(f, self._parent)
return self._wrap_result(result) |
Returns system information as a dict | def get_sys_info():
"Returns system information as a dict"
blob = []
# get full commit hash
commit = None
if os.path.isdir(".git") and os.path.isdir("pandas"):
try:
pipe = subprocess.Popen('git log --format="%H" -n 1'.split(" "),
stdout=subprocess.PIPE,
stderr=subprocess.PIPE)
so, serr = pipe.communicate()
except (OSError, ValueError):
pass
else:
if pipe.returncode == 0:
commit = so
try:
commit = so.decode('utf-8')
except ValueError:
pass
commit = commit.strip().strip('"')
blob.append(('commit', commit))
try:
(sysname, nodename, release,
version, machine, processor) = platform.uname()
blob.extend([
("python", '.'.join(map(str, sys.version_info))),
("python-bits", struct.calcsize("P") * 8),
("OS", "{sysname}".format(sysname=sysname)),
("OS-release", "{release}".format(release=release)),
# ("Version", "{version}".format(version=version)),
("machine", "{machine}".format(machine=machine)),
("processor", "{processor}".format(processor=processor)),
("byteorder", "{byteorder}".format(byteorder=sys.byteorder)),
("LC_ALL", "{lc}".format(lc=os.environ.get('LC_ALL', "None"))),
("LANG", "{lang}".format(lang=os.environ.get('LANG', "None"))),
("LOCALE", '.'.join(map(str, locale.getlocale()))),
])
except (KeyError, ValueError):
pass
return blob |
Yields all GroupBy member defs for DataFrame/Series names in whitelist.
Parameters
----------
base : class
base class
klass : class
class where members are defined.
Should be Series or DataFrame
whitelist : list
list of names of klass methods to be constructed
Returns
-------
The generator yields a sequence of strings, each suitable for exec'ing,
that define implementations of the named methods for DataFrameGroupBy
or SeriesGroupBy.
Since we don't want to override methods explicitly defined in the
base class, any such name is skipped. | def whitelist_method_generator(base, klass, whitelist):
"""
Yields all GroupBy member defs for DataFrame/Series names in whitelist.
Parameters
----------
base : class
base class
klass : class
class where members are defined.
Should be Series or DataFrame
whitelist : list
list of names of klass methods to be constructed
Returns
-------
The generator yields a sequence of strings, each suitable for exec'ing,
that define implementations of the named methods for DataFrameGroupBy
or SeriesGroupBy.
Since we don't want to override methods explicitly defined in the
base class, any such name is skipped.
"""
method_wrapper_template = \
"""def %(name)s(%(sig)s) :
\"""
%(doc)s
\"""
f = %(self)s.__getattr__('%(name)s')
return f(%(args)s)"""
property_wrapper_template = \
"""@property
def %(name)s(self) :
\"""%(doc)s\"""
return self.__getattr__('%(name)s')"""
for name in whitelist:
# don't override anything that was explicitly defined
# in the base class
if hasattr(base, name):
continue
# ugly, but we need the name string itself in the method.
f = getattr(klass, name)
doc = f.__doc__
doc = doc if type(doc) == str else ''
if isinstance(f, types.MethodType):
wrapper_template = method_wrapper_template
decl, args = make_signature(f)
# pass args by name to f because otherwise
# GroupBy._make_wrapper won't know whether
# we passed in an axis parameter.
args_by_name = ['{0}={0}'.format(arg) for arg in args[1:]]
params = {'name': name,
'doc': doc,
'sig': ','.join(decl),
'self': args[0],
'args': ','.join(args_by_name)}
else:
wrapper_template = property_wrapper_template
params = {'name': name, 'doc': doc}
yield wrapper_template % params |
Dispatch to apply. | def _dispatch(name, *args, **kwargs):
"""
Dispatch to apply.
"""
def outer(self, *args, **kwargs):
def f(x):
x = self._shallow_copy(x, groupby=self._groupby)
return getattr(x, name)(*args, **kwargs)
return self._groupby.apply(f)
outer.__name__ = name
return outer |
Sub-classes to define. Return a sliced object.
Parameters
----------
key : string / list of selections
ndim : 1,2
requested ndim of result
subset : object, default None
subset to act on | def _gotitem(self, key, ndim, subset=None):
"""
Sub-classes to define. Return a sliced object.
Parameters
----------
key : string / list of selections
ndim : 1,2
requested ndim of result
subset : object, default None
subset to act on
"""
# create a new object to prevent aliasing
if subset is None:
subset = self.obj
# we need to make a shallow copy of ourselves
# with the same groupby
kwargs = {attr: getattr(self, attr) for attr in self._attributes}
# Try to select from a DataFrame, falling back to a Series
try:
groupby = self._groupby[key]
except IndexError:
groupby = self._groupby
self = self.__class__(subset,
groupby=groupby,
parent=self,
**kwargs)
self._reset_cache()
if subset.ndim == 2:
if is_scalar(key) and key in subset or is_list_like(key):
self._selection = key
return self |
Convert bytes and non-string into Python 3 str | def to_str(s):
"""
Convert bytes and non-string into Python 3 str
"""
if isinstance(s, bytes):
s = s.decode('utf-8')
elif not isinstance(s, str):
s = str(s)
return s |
Bind the name/qualname attributes of the function | def set_function_name(f, name, cls):
"""
Bind the name/qualname attributes of the function
"""
f.__name__ = name
f.__qualname__ = '{klass}.{name}'.format(
klass=cls.__name__,
name=name)
f.__module__ = cls.__module__
return f |
Raise exception with existing traceback.
If traceback is not passed, uses sys.exc_info() to get traceback. | def raise_with_traceback(exc, traceback=Ellipsis):
"""
Raise exception with existing traceback.
If traceback is not passed, uses sys.exc_info() to get traceback.
"""
if traceback == Ellipsis:
_, _, traceback = sys.exc_info()
raise exc.with_traceback(traceback) |
converts a style_dict to an openpyxl style object
Parameters
----------
style_dict : style dictionary to convert | def _convert_to_style(cls, style_dict):
"""
converts a style_dict to an openpyxl style object
Parameters
----------
style_dict : style dictionary to convert
"""
from openpyxl.style import Style
xls_style = Style()
for key, value in style_dict.items():
for nk, nv in value.items():
if key == "borders":
(xls_style.borders.__getattribute__(nk)
.__setattr__('border_style', nv))
else:
xls_style.__getattribute__(key).__setattr__(nk, nv)
return xls_style |
Convert a style_dict to a set of kwargs suitable for initializing
or updating-on-copy an openpyxl v2 style object
Parameters
----------
style_dict : dict
A dict with zero or more of the following keys (or their synonyms).
'font'
'fill'
'border' ('borders')
'alignment'
'number_format'
'protection'
Returns
-------
style_kwargs : dict
A dict with the same, normalized keys as ``style_dict`` but each
value has been replaced with a native openpyxl style object of the
appropriate class. | def _convert_to_style_kwargs(cls, style_dict):
"""
Convert a style_dict to a set of kwargs suitable for initializing
or updating-on-copy an openpyxl v2 style object
Parameters
----------
style_dict : dict
A dict with zero or more of the following keys (or their synonyms).
'font'
'fill'
'border' ('borders')
'alignment'
'number_format'
'protection'
Returns
-------
style_kwargs : dict
A dict with the same, normalized keys as ``style_dict`` but each
value has been replaced with a native openpyxl style object of the
appropriate class.
"""
_style_key_map = {
'borders': 'border',
}
style_kwargs = {}
for k, v in style_dict.items():
if k in _style_key_map:
k = _style_key_map[k]
_conv_to_x = getattr(cls, '_convert_to_{k}'.format(k=k),
lambda x: None)
new_v = _conv_to_x(v)
if new_v:
style_kwargs[k] = new_v
return style_kwargs |
Convert ``color_spec`` to an openpyxl v2 Color object
Parameters
----------
color_spec : str, dict
A 32-bit ARGB hex string, or a dict with zero or more of the
following keys.
'rgb'
'indexed'
'auto'
'theme'
'tint'
'index'
'type'
Returns
-------
color : openpyxl.styles.Color | def _convert_to_color(cls, color_spec):
"""
Convert ``color_spec`` to an openpyxl v2 Color object
Parameters
----------
color_spec : str, dict
A 32-bit ARGB hex string, or a dict with zero or more of the
following keys.
'rgb'
'indexed'
'auto'
'theme'
'tint'
'index'
'type'
Returns
-------
color : openpyxl.styles.Color
"""
from openpyxl.styles import Color
if isinstance(color_spec, str):
return Color(color_spec)
else:
return Color(**color_spec) |
Convert ``font_dict`` to an openpyxl v2 Font object
Parameters
----------
font_dict : dict
A dict with zero or more of the following keys (or their synonyms).
'name'
'size' ('sz')
'bold' ('b')
'italic' ('i')
'underline' ('u')
'strikethrough' ('strike')
'color'
'vertAlign' ('vertalign')
'charset'
'scheme'
'family'
'outline'
'shadow'
'condense'
Returns
-------
font : openpyxl.styles.Font | def _convert_to_font(cls, font_dict):
"""
Convert ``font_dict`` to an openpyxl v2 Font object
Parameters
----------
font_dict : dict
A dict with zero or more of the following keys (or their synonyms).
'name'
'size' ('sz')
'bold' ('b')
'italic' ('i')
'underline' ('u')
'strikethrough' ('strike')
'color'
'vertAlign' ('vertalign')
'charset'
'scheme'
'family'
'outline'
'shadow'
'condense'
Returns
-------
font : openpyxl.styles.Font
"""
from openpyxl.styles import Font
_font_key_map = {
'sz': 'size',
'b': 'bold',
'i': 'italic',
'u': 'underline',
'strike': 'strikethrough',
'vertalign': 'vertAlign',
}
font_kwargs = {}
for k, v in font_dict.items():
if k in _font_key_map:
k = _font_key_map[k]
if k == 'color':
v = cls._convert_to_color(v)
font_kwargs[k] = v
return Font(**font_kwargs) |
Convert ``fill_dict`` to an openpyxl v2 Fill object
Parameters
----------
fill_dict : dict
A dict with one or more of the following keys (or their synonyms),
'fill_type' ('patternType', 'patterntype')
'start_color' ('fgColor', 'fgcolor')
'end_color' ('bgColor', 'bgcolor')
or one or more of the following keys (or their synonyms).
'type' ('fill_type')
'degree'
'left'
'right'
'top'
'bottom'
'stop'
Returns
-------
fill : openpyxl.styles.Fill | def _convert_to_fill(cls, fill_dict):
"""
Convert ``fill_dict`` to an openpyxl v2 Fill object
Parameters
----------
fill_dict : dict
A dict with one or more of the following keys (or their synonyms),
'fill_type' ('patternType', 'patterntype')
'start_color' ('fgColor', 'fgcolor')
'end_color' ('bgColor', 'bgcolor')
or one or more of the following keys (or their synonyms).
'type' ('fill_type')
'degree'
'left'
'right'
'top'
'bottom'
'stop'
Returns
-------
fill : openpyxl.styles.Fill
"""
from openpyxl.styles import PatternFill, GradientFill
_pattern_fill_key_map = {
'patternType': 'fill_type',
'patterntype': 'fill_type',
'fgColor': 'start_color',
'fgcolor': 'start_color',
'bgColor': 'end_color',
'bgcolor': 'end_color',
}
_gradient_fill_key_map = {
'fill_type': 'type',
}
pfill_kwargs = {}
gfill_kwargs = {}
for k, v in fill_dict.items():
pk = gk = None
if k in _pattern_fill_key_map:
pk = _pattern_fill_key_map[k]
if k in _gradient_fill_key_map:
gk = _gradient_fill_key_map[k]
if pk in ['start_color', 'end_color']:
v = cls._convert_to_color(v)
if gk == 'stop':
v = cls._convert_to_stop(v)
if pk:
pfill_kwargs[pk] = v
elif gk:
gfill_kwargs[gk] = v
else:
pfill_kwargs[k] = v
gfill_kwargs[k] = v
try:
return PatternFill(**pfill_kwargs)
except TypeError:
return GradientFill(**gfill_kwargs) |
Convert ``side_spec`` to an openpyxl v2 Side object
Parameters
----------
side_spec : str, dict
A string specifying the border style, or a dict with zero or more
of the following keys (or their synonyms).
'style' ('border_style')
'color'
Returns
-------
side : openpyxl.styles.Side | def _convert_to_side(cls, side_spec):
"""
Convert ``side_spec`` to an openpyxl v2 Side object
Parameters
----------
side_spec : str, dict
A string specifying the border style, or a dict with zero or more
of the following keys (or their synonyms).
'style' ('border_style')
'color'
Returns
-------
side : openpyxl.styles.Side
"""
from openpyxl.styles import Side
_side_key_map = {
'border_style': 'style',
}
if isinstance(side_spec, str):
return Side(style=side_spec)
side_kwargs = {}
for k, v in side_spec.items():
if k in _side_key_map:
k = _side_key_map[k]
if k == 'color':
v = cls._convert_to_color(v)
side_kwargs[k] = v
return Side(**side_kwargs) |
Convert ``border_dict`` to an openpyxl v2 Border object
Parameters
----------
border_dict : dict
A dict with zero or more of the following keys (or their synonyms).
'left'
'right'
'top'
'bottom'
'diagonal'
'diagonal_direction'
'vertical'
'horizontal'
'diagonalUp' ('diagonalup')
'diagonalDown' ('diagonaldown')
'outline'
Returns
-------
border : openpyxl.styles.Border | def _convert_to_border(cls, border_dict):
"""
Convert ``border_dict`` to an openpyxl v2 Border object
Parameters
----------
border_dict : dict
A dict with zero or more of the following keys (or their synonyms).
'left'
'right'
'top'
'bottom'
'diagonal'
'diagonal_direction'
'vertical'
'horizontal'
'diagonalUp' ('diagonalup')
'diagonalDown' ('diagonaldown')
'outline'
Returns
-------
border : openpyxl.styles.Border
"""
from openpyxl.styles import Border
_border_key_map = {
'diagonalup': 'diagonalUp',
'diagonaldown': 'diagonalDown',
}
border_kwargs = {}
for k, v in border_dict.items():
if k in _border_key_map:
k = _border_key_map[k]
if k == 'color':
v = cls._convert_to_color(v)
if k in ['left', 'right', 'top', 'bottom', 'diagonal']:
v = cls._convert_to_side(v)
border_kwargs[k] = v
return Border(**border_kwargs) |
construct and return a row or column based frame apply object | def frame_apply(obj, func, axis=0, broadcast=None,
raw=False, reduce=None, result_type=None,
ignore_failures=False,
args=None, kwds=None):
""" construct and return a row or column based frame apply object """
axis = obj._get_axis_number(axis)
if axis == 0:
klass = FrameRowApply
elif axis == 1:
klass = FrameColumnApply
return klass(obj, func, broadcast=broadcast,
raw=raw, reduce=reduce, result_type=result_type,
ignore_failures=ignore_failures,
args=args, kwds=kwds) |
we have an empty result; at least 1 axis is 0
we will try to apply the function to an empty
series in order to see if this is a reduction function | def apply_empty_result(self):
"""
we have an empty result; at least 1 axis is 0
we will try to apply the function to an empty
series in order to see if this is a reduction function
"""
# we are not asked to reduce or infer reduction
# so just return a copy of the existing object
if self.result_type not in ['reduce', None]:
return self.obj.copy()
# we may need to infer
reduce = self.result_type == 'reduce'
from pandas import Series
if not reduce:
EMPTY_SERIES = Series([])
try:
r = self.f(EMPTY_SERIES, *self.args, **self.kwds)
reduce = not isinstance(r, Series)
except Exception:
pass
if reduce:
return self.obj._constructor_sliced(np.nan, index=self.agg_axis)
else:
return self.obj.copy() |
compute the results | def get_result(self):
""" compute the results """
# dispatch to agg
if is_list_like(self.f) or is_dict_like(self.f):
return self.obj.aggregate(self.f, axis=self.axis,
*self.args, **self.kwds)
# all empty
if len(self.columns) == 0 and len(self.index) == 0:
return self.apply_empty_result()
# string dispatch
if isinstance(self.f, str):
# Support for `frame.transform('method')`
# Some methods (shift, etc.) require the axis argument, others
# don't, so inspect and insert if necessary.
func = getattr(self.obj, self.f)
sig = inspect.getfullargspec(func)
if 'axis' in sig.args:
self.kwds['axis'] = self.axis
return func(*self.args, **self.kwds)
# ufunc
elif isinstance(self.f, np.ufunc):
with np.errstate(all='ignore'):
results = self.obj._data.apply('apply', func=self.f)
return self.obj._constructor(data=results, index=self.index,
columns=self.columns, copy=False)
# broadcasting
if self.result_type == 'broadcast':
return self.apply_broadcast()
# one axis empty
elif not all(self.obj.shape):
return self.apply_empty_result()
# raw
elif self.raw and not self.obj._is_mixed_type:
return self.apply_raw()
return self.apply_standard() |
apply to the values as a numpy array | def apply_raw(self):
""" apply to the values as a numpy array """
try:
result = reduction.reduce(self.values, self.f, axis=self.axis)
except Exception:
result = np.apply_along_axis(self.f, self.axis, self.values)
# TODO: mixed type case
if result.ndim == 2:
return self.obj._constructor(result,
index=self.index,
columns=self.columns)
else:
return self.obj._constructor_sliced(result,
index=self.agg_axis) |
return the results for the rows | def wrap_results_for_axis(self):
""" return the results for the rows """
results = self.results
result = self.obj._constructor(data=results)
if not isinstance(results[0], ABCSeries):
try:
result.index = self.res_columns
except ValueError:
pass
try:
result.columns = self.res_index
except ValueError:
pass
return result |
return the results for the columns | def wrap_results_for_axis(self):
""" return the results for the columns """
results = self.results
# we have requested to expand
if self.result_type == 'expand':
result = self.infer_to_same_shape()
# we have a non-series and don't want inference
elif not isinstance(results[0], ABCSeries):
from pandas import Series
result = Series(results)
result.index = self.res_index
# we may want to infer results
else:
result = self.infer_to_same_shape()
return result |
infer the results to the same shape as the input object | def infer_to_same_shape(self):
""" infer the results to the same shape as the input object """
results = self.results
result = self.obj._constructor(data=results)
result = result.T
# set the index
result.index = self.res_index
# infer dtypes
result = result.infer_objects()
return result |
Numpy version of itertools.product.
Sometimes faster (for large inputs)...
Parameters
----------
X : list-like of list-likes
Returns
-------
product : list of ndarrays
Examples
--------
>>> cartesian_product([list('ABC'), [1, 2]])
[array(['A', 'A', 'B', 'B', 'C', 'C'], dtype='|S1'),
array([1, 2, 1, 2, 1, 2])]
See Also
--------
itertools.product : Cartesian product of input iterables. Equivalent to
nested for-loops. | def cartesian_product(X):
"""
Numpy version of itertools.product.
Sometimes faster (for large inputs)...
Parameters
----------
X : list-like of list-likes
Returns
-------
product : list of ndarrays
Examples
--------
>>> cartesian_product([list('ABC'), [1, 2]])
[array(['A', 'A', 'B', 'B', 'C', 'C'], dtype='|S1'),
array([1, 2, 1, 2, 1, 2])]
See Also
--------
itertools.product : Cartesian product of input iterables. Equivalent to
nested for-loops.
"""
msg = "Input must be a list-like of list-likes"
if not is_list_like(X):
raise TypeError(msg)
for x in X:
if not is_list_like(x):
raise TypeError(msg)
if len(X) == 0:
return []
lenX = np.fromiter((len(x) for x in X), dtype=np.intp)
cumprodX = np.cumproduct(lenX)
a = np.roll(cumprodX, 1)
a[0] = 1
if cumprodX[-1] != 0:
b = cumprodX[-1] / cumprodX
else:
# if any factor is empty, the cartesian product is empty
b = np.zeros_like(cumprodX)
return [np.tile(np.repeat(np.asarray(com.values_from_object(x)), b[i]),
np.product(a[i]))
for i, x in enumerate(X)] |
Returns the url without the s3:// part | def _strip_schema(url):
"""Returns the url without the s3:// part"""
result = parse_url(url, allow_fragments=False)
return result.netloc + result.path |
Preview version of Xception network. Not tested yet - use at own risk. No pretrained model yet. | def xception(c, k=8, n_middle=8):
"Preview version of Xception network. Not tested yet - use at own risk. No pretrained model yet."
layers = [
conv(3, k*4, 3, 2),
conv(k*4, k*8, 3),
ConvSkip(k*8, k*16, act=False),
ConvSkip(k*16, k*32),
ConvSkip(k*32, k*91),
]
for i in range(n_middle): layers.append(middle_flow(k*91))
layers += [
ConvSkip(k*91,k*128),
sep_conv(k*128,k*192,act=False),
sep_conv(k*192,k*256),
nn.ReLU(),
nn.AdaptiveAvgPool2d(1),
Flatten(),
nn.Linear(k*256,c)
]
return nn.Sequential(*layers) |
Method returns a RNN_Learner object, that wraps an instance of the RNN_Encoder module.
Args:
opt_fn (Optimizer): the torch optimizer function to use
emb_sz (int): embedding size
n_hid (int): number of hidden inputs
n_layers (int): number of hidden layers
kwargs: other arguments
Returns:
An instance of the RNN_Learner class. | def get_model(self, opt_fn, emb_sz, n_hid, n_layers, **kwargs):
""" Method returns a RNN_Learner object, that wraps an instance of the RNN_Encoder module.
Args:
opt_fn (Optimizer): the torch optimizer function to use
emb_sz (int): embedding size
n_hid (int): number of hidden inputs
n_layers (int): number of hidden layers
kwargs: other arguments
Returns:
An instance of the RNN_Learner class.
"""
m = get_language_model(self.nt, emb_sz, n_hid, n_layers, self.pad_idx, **kwargs)
model = SingleModel(to_gpu(m))
return RNN_Learner(self, model, opt_fn=opt_fn) |
Method used to instantiate a LanguageModelData object that can be used for a
supported nlp task.
Args:
path (str): the absolute path in which temporary model data will be saved
field (Field): torchtext field
train (str): file location of the training data
validation (str): file location of the validation data
test (str): file location of the testing data
bs (int): batch size to use
bptt (int): back propagation through time hyper-parameter
kwargs: other arguments
Returns:
a LanguageModelData instance, which most importantly, provides us the datasets for training,
validation, and testing
Note:
The train, validation, and test path can be pointed to any file (or folder) that contains a valid
text corpus. | def from_text_files(cls, path, field, train, validation, test=None, bs=64, bptt=70, **kwargs):
""" Method used to instantiate a LanguageModelData object that can be used for a
supported nlp task.
Args:
path (str): the absolute path in which temporary model data will be saved
field (Field): torchtext field
train (str): file location of the training data
validation (str): file location of the validation data
test (str): file location of the testing data
bs (int): batch size to use
bptt (int): back propagation through time hyper-parameter
kwargs: other arguments
Returns:
a LanguageModelData instance, which most importantly, provides us the datasets for training,
validation, and testing
Note:
The train, validation, and test path can be pointed to any file (or folder) that contains a valid
text corpus.
"""
trn_ds, val_ds, test_ds = ConcatTextDataset.splits(
path, text_field=field, train=train, validation=validation, test=test)
return cls(path, field, trn_ds, val_ds, test_ds, bs, bptt, **kwargs) |
Return list of files in `path` that have a suffix in `extensions`; optionally `recurse`. | def get_files(path:PathOrStr, extensions:Collection[str]=None, recurse:bool=False,
include:Optional[Collection[str]]=None)->FilePathList:
"Return list of files in `path` that have a suffix in `extensions`; optionally `recurse`."
if recurse:
res = []
for i,(p,d,f) in enumerate(os.walk(path)):
# skip hidden dirs
if include is not None and i==0: d[:] = [o for o in d if o in include]
else: d[:] = [o for o in d if not o.startswith('.')]
res += _get_files(path, p, f, extensions)
return res
else:
f = [o.name for o in os.scandir(path) if o.is_file()]
return _get_files(path, path, f, extensions) |
Load an empty `DataBunch` from the exported file in `path/fname` with optional `tfms`. | def _databunch_load_empty(cls, path, fname:str='export.pkl'):
"Load an empty `DataBunch` from the exported file in `path/fname` with optional `tfms`."
sd = LabelLists.load_empty(path, fn=fname)
return sd.databunch() |
Apply `processor` or `self.processor` to `self`. | def process(self, processor:PreProcessors=None):
"Apply `processor` or `self.processor` to `self`."
if processor is not None: self.processor = processor
self.processor = listify(self.processor)
for p in self.processor: p.process(self)
return self |
Apply `processor` or `self.processor` to `item`. | def process_one(self, item:ItemBase, processor:PreProcessors=None):
"Apply `processor` or `self.processor` to `item`."
if processor is not None: self.processor = processor
self.processor = listify(self.processor)
for p in self.processor: item = p.process_one(item)
return item |
Reconstruct one of the underlying item for its data `t`. | def reconstruct(self, t:Tensor, x:Tensor=None):
"Reconstruct one of the underlying item for its data `t`."
return self[0].reconstruct(t,x) if has_arg(self[0].reconstruct, 'x') else self[0].reconstruct(t) |
Create a new `ItemList` from `items`, keeping the same attributes. | def new(self, items:Iterator, processor:PreProcessors=None, **kwargs)->'ItemList':
"Create a new `ItemList` from `items`, keeping the same attributes."
processor = ifnone(processor, self.processor)
copy_d = {o:getattr(self,o) for o in self.copy_new}
kwargs = {**copy_d, **kwargs}
return self.__class__(items=items, processor=processor, **kwargs) |
Create an `ItemList` in `path` from the filenames that have a suffix in `extensions`.
`recurse` determines if we search subfolders. | def from_folder(cls, path:PathOrStr, extensions:Collection[str]=None, recurse:bool=True,
include:Optional[Collection[str]]=None, processor:PreProcessors=None, **kwargs)->'ItemList':
"""Create an `ItemList` in `path` from the filenames that have a suffix in `extensions`.
`recurse` determines if we search subfolders."""
path = Path(path)
return cls(get_files(path, extensions, recurse=recurse, include=include), path=path, processor=processor, **kwargs) |
Create an `ItemList` in `path` from the inputs in the `cols` of `df`. | def from_df(cls, df:DataFrame, path:PathOrStr='.', cols:IntsOrStrs=0, processor:PreProcessors=None, **kwargs)->'ItemList':
"Create an `ItemList` in `path` from the inputs in the `cols` of `df`."
inputs = df.iloc[:,df_names_to_idx(cols, df)]
assert inputs.isna().sum().sum() == 0, f"You have NaN values in column(s) {cols} of your dataframe, please fix it."
res = cls(items=_maybe_squeeze(inputs.values), path=path, inner_df=df, processor=processor, **kwargs)
return res |
Create an `ItemList` in `path` from the inputs in the `cols` of `path/csv_name` | def from_csv(cls, path:PathOrStr, csv_name:str, cols:IntsOrStrs=0, delimiter:str=None, header:str='infer',
processor:PreProcessors=None, **kwargs)->'ItemList':
"""Create an `ItemList` in `path` from the inputs in the `cols` of `path/csv_name`"""
df = pd.read_csv(Path(path)/csv_name, delimiter=delimiter, header=header)
return cls.from_df(df, path=path, cols=cols, processor=processor, **kwargs) |
Use only a sample of `sample_pct`of the full dataset and an optional `seed`. | def use_partial_data(self, sample_pct:float=0.01, seed:int=None)->'ItemList':
"Use only a sample of `sample_pct`of the full dataset and an optional `seed`."
if seed is not None: np.random.seed(seed)
rand_idx = np.random.permutation(range_of(self))
cut = int(sample_pct * len(self))
return self[rand_idx[:cut]] |
Save `self.items` to `fn` in `self.path`. | def to_text(self, fn:str):
"Save `self.items` to `fn` in `self.path`."
with open(self.path/fn, 'w') as f: f.writelines([f'{o}\n' for o in self._relative_item_paths()]) |
Only keep elements for which `func` returns `True`. | def filter_by_func(self, func:Callable)->'ItemList':
"Only keep elements for which `func` returns `True`."
self.items = array([o for o in self.items if func(o)])
return self |
Only keep filenames in `include` folder or reject the ones in `exclude`. | def filter_by_folder(self, include=None, exclude=None):
"Only keep filenames in `include` folder or reject the ones in `exclude`."
include,exclude = listify(include),listify(exclude)
def _inner(o):
if isinstance(o, Path): n = o.relative_to(self.path).parts[0]
else: n = o.split(os.path.sep)[len(str(self.path).split(os.path.sep))]
if include and not n in include: return False
if exclude and n in exclude: return False
return True
return self.filter_by_func(_inner) |
Keep random sample of `items` with probability `p` and an optional `seed`. | def filter_by_rand(self, p:float, seed:int=None):
"Keep random sample of `items` with probability `p` and an optional `seed`."
if seed is not None: np.random.seed(seed)
return self.filter_by_func(lambda o: rand_bool(p)) |
Don't split the data and create an empty validation set. | def split_none(self):
"Don't split the data and create an empty validation set."
val = self[[]]
val.ignore_empty = True
return self._split(self.path, self, val) |
Split the data between `train` and `valid`. | def split_by_list(self, train, valid):
"Split the data between `train` and `valid`."
return self._split(self.path, train, valid) |
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