INSTRUCTION
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Concatenate list of single blocks of the same type. | def concat_same_type(self, to_concat, placement=None):
"""
Concatenate list of single blocks of the same type.
"""
values = self._concatenator([blk.values for blk in to_concat],
axis=self.ndim - 1)
return self.make_block_same_class(
values, placement=placement or slice(0, len(values), 1)) |
Delete given loc(-s) from block in-place. | def delete(self, loc):
"""
Delete given loc(-s) from block in-place.
"""
self.values = np.delete(self.values, loc, 0)
self.mgr_locs = self.mgr_locs.delete(loc) |
apply the function to my values; return a block if we are not
one | def apply(self, func, **kwargs):
""" apply the function to my values; return a block if we are not
one
"""
with np.errstate(all='ignore'):
result = func(self.values, **kwargs)
if not isinstance(result, Block):
result = self.make_block(values=_block_shape(result,
ndim=self.ndim))
return result |
fillna on the block with the value. If we fail, then convert to
ObjectBlock and try again | def fillna(self, value, limit=None, inplace=False, downcast=None):
""" fillna on the block with the value. If we fail, then convert to
ObjectBlock and try again
"""
inplace = validate_bool_kwarg(inplace, 'inplace')
if not self._can_hold_na:
if inplace:
return self
else:
return self.copy()
mask = isna(self.values)
if limit is not None:
if not is_integer(limit):
raise ValueError('Limit must be an integer')
if limit < 1:
raise ValueError('Limit must be greater than 0')
if self.ndim > 2:
raise NotImplementedError("number of dimensions for 'fillna' "
"is currently limited to 2")
mask[mask.cumsum(self.ndim - 1) > limit] = False
# fillna, but if we cannot coerce, then try again as an ObjectBlock
try:
values, _ = self._try_coerce_args(self.values, value)
blocks = self.putmask(mask, value, inplace=inplace)
blocks = [b.make_block(values=self._try_coerce_result(b.values))
for b in blocks]
return self._maybe_downcast(blocks, downcast)
except (TypeError, ValueError):
# we can't process the value, but nothing to do
if not mask.any():
return self if inplace else self.copy()
# operate column-by-column
def f(m, v, i):
block = self.coerce_to_target_dtype(value)
# slice out our block
if i is not None:
block = block.getitem_block(slice(i, i + 1))
return block.fillna(value,
limit=limit,
inplace=inplace,
downcast=None)
return self.split_and_operate(mask, f, inplace) |
split the block per-column, and apply the callable f
per-column, return a new block for each. Handle
masking which will not change a block unless needed.
Parameters
----------
mask : 2-d boolean mask
f : callable accepting (1d-mask, 1d values, indexer)
inplace : boolean
Returns
-------
list of blocks | def split_and_operate(self, mask, f, inplace):
"""
split the block per-column, and apply the callable f
per-column, return a new block for each. Handle
masking which will not change a block unless needed.
Parameters
----------
mask : 2-d boolean mask
f : callable accepting (1d-mask, 1d values, indexer)
inplace : boolean
Returns
-------
list of blocks
"""
if mask is None:
mask = np.ones(self.shape, dtype=bool)
new_values = self.values
def make_a_block(nv, ref_loc):
if isinstance(nv, Block):
block = nv
elif isinstance(nv, list):
block = nv[0]
else:
# Put back the dimension that was taken from it and make
# a block out of the result.
try:
nv = _block_shape(nv, ndim=self.ndim)
except (AttributeError, NotImplementedError):
pass
block = self.make_block(values=nv,
placement=ref_loc)
return block
# ndim == 1
if self.ndim == 1:
if mask.any():
nv = f(mask, new_values, None)
else:
nv = new_values if inplace else new_values.copy()
block = make_a_block(nv, self.mgr_locs)
return [block]
# ndim > 1
new_blocks = []
for i, ref_loc in enumerate(self.mgr_locs):
m = mask[i]
v = new_values[i]
# need a new block
if m.any():
nv = f(m, v, i)
else:
nv = v if inplace else v.copy()
block = make_a_block(nv, [ref_loc])
new_blocks.append(block)
return new_blocks |
try to downcast each item to the dict of dtypes if present | def downcast(self, dtypes=None):
""" try to downcast each item to the dict of dtypes if present """
# turn it off completely
if dtypes is False:
return self
values = self.values
# single block handling
if self._is_single_block:
# try to cast all non-floats here
if dtypes is None:
dtypes = 'infer'
nv = maybe_downcast_to_dtype(values, dtypes)
return self.make_block(nv)
# ndim > 1
if dtypes is None:
return self
if not (dtypes == 'infer' or isinstance(dtypes, dict)):
raise ValueError("downcast must have a dictionary or 'infer' as "
"its argument")
# operate column-by-column
# this is expensive as it splits the blocks items-by-item
def f(m, v, i):
if dtypes == 'infer':
dtype = 'infer'
else:
raise AssertionError("dtypes as dict is not supported yet")
if dtype is not None:
v = maybe_downcast_to_dtype(v, dtype)
return v
return self.split_and_operate(None, f, False) |
Coerce to the new type
Parameters
----------
dtype : str, dtype convertible
copy : boolean, default False
copy if indicated
errors : str, {'raise', 'ignore'}, default 'ignore'
- ``raise`` : allow exceptions to be raised
- ``ignore`` : suppress exceptions. On error return original object
Returns
-------
Block | def _astype(self, dtype, copy=False, errors='raise', values=None,
**kwargs):
"""Coerce to the new type
Parameters
----------
dtype : str, dtype convertible
copy : boolean, default False
copy if indicated
errors : str, {'raise', 'ignore'}, default 'ignore'
- ``raise`` : allow exceptions to be raised
- ``ignore`` : suppress exceptions. On error return original object
Returns
-------
Block
"""
errors_legal_values = ('raise', 'ignore')
if errors not in errors_legal_values:
invalid_arg = ("Expected value of kwarg 'errors' to be one of {}. "
"Supplied value is '{}'".format(
list(errors_legal_values), errors))
raise ValueError(invalid_arg)
if (inspect.isclass(dtype) and
issubclass(dtype, (PandasExtensionDtype, ExtensionDtype))):
msg = ("Expected an instance of {}, but got the class instead. "
"Try instantiating 'dtype'.".format(dtype.__name__))
raise TypeError(msg)
# may need to convert to categorical
if self.is_categorical_astype(dtype):
# deprecated 17636
if ('categories' in kwargs or 'ordered' in kwargs):
if isinstance(dtype, CategoricalDtype):
raise TypeError(
"Cannot specify a CategoricalDtype and also "
"`categories` or `ordered`. Use "
"`dtype=CategoricalDtype(categories, ordered)`"
" instead.")
warnings.warn("specifying 'categories' or 'ordered' in "
".astype() is deprecated; pass a "
"CategoricalDtype instead",
FutureWarning, stacklevel=7)
categories = kwargs.get('categories', None)
ordered = kwargs.get('ordered', None)
if com._any_not_none(categories, ordered):
dtype = CategoricalDtype(categories, ordered)
if is_categorical_dtype(self.values):
# GH 10696/18593: update an existing categorical efficiently
return self.make_block(self.values.astype(dtype, copy=copy))
return self.make_block(Categorical(self.values, dtype=dtype))
dtype = pandas_dtype(dtype)
# astype processing
if is_dtype_equal(self.dtype, dtype):
if copy:
return self.copy()
return self
try:
# force the copy here
if values is None:
if self.is_extension:
values = self.values.astype(dtype)
else:
if issubclass(dtype.type, str):
# use native type formatting for datetime/tz/timedelta
if self.is_datelike:
values = self.to_native_types()
# astype formatting
else:
values = self.get_values()
else:
values = self.get_values(dtype=dtype)
# _astype_nansafe works fine with 1-d only
values = astype_nansafe(values.ravel(), dtype, copy=True)
# TODO(extension)
# should we make this attribute?
try:
values = values.reshape(self.shape)
except AttributeError:
pass
newb = make_block(values, placement=self.mgr_locs,
ndim=self.ndim)
except Exception: # noqa: E722
if errors == 'raise':
raise
newb = self.copy() if copy else self
if newb.is_numeric and self.is_numeric:
if newb.shape != self.shape:
raise TypeError(
"cannot set astype for copy = [{copy}] for dtype "
"({dtype} [{shape}]) to different shape "
"({newb_dtype} [{newb_shape}])".format(
copy=copy, dtype=self.dtype.name,
shape=self.shape, newb_dtype=newb.dtype.name,
newb_shape=newb.shape))
return newb |
require the same dtype as ourselves | def _can_hold_element(self, element):
""" require the same dtype as ourselves """
dtype = self.values.dtype.type
tipo = maybe_infer_dtype_type(element)
if tipo is not None:
return issubclass(tipo.type, dtype)
return isinstance(element, dtype) |
try to cast the result to our original type, we may have
roundtripped thru object in the mean-time | def _try_cast_result(self, result, dtype=None):
""" try to cast the result to our original type, we may have
roundtripped thru object in the mean-time
"""
if dtype is None:
dtype = self.dtype
if self.is_integer or self.is_bool or self.is_datetime:
pass
elif self.is_float and result.dtype == self.dtype:
# protect against a bool/object showing up here
if isinstance(dtype, str) and dtype == 'infer':
return result
if not isinstance(dtype, type):
dtype = dtype.type
if issubclass(dtype, (np.bool_, np.object_)):
if issubclass(dtype, np.bool_):
if isna(result).all():
return result.astype(np.bool_)
else:
result = result.astype(np.object_)
result[result == 1] = True
result[result == 0] = False
return result
else:
return result.astype(np.object_)
return result
# may need to change the dtype here
return maybe_downcast_to_dtype(result, dtype) |
provide coercion to our input arguments | def _try_coerce_args(self, values, other):
""" provide coercion to our input arguments """
if np.any(notna(other)) and not self._can_hold_element(other):
# coercion issues
# let higher levels handle
raise TypeError("cannot convert {} to an {}".format(
type(other).__name__,
type(self).__name__.lower().replace('Block', '')))
return values, other |
convert to our native types format, slicing if desired | def to_native_types(self, slicer=None, na_rep='nan', quoting=None,
**kwargs):
""" convert to our native types format, slicing if desired """
values = self.get_values()
if slicer is not None:
values = values[:, slicer]
mask = isna(values)
if not self.is_object and not quoting:
values = values.astype(str)
else:
values = np.array(values, dtype='object')
values[mask] = na_rep
return values |
copy constructor | def copy(self, deep=True):
""" copy constructor """
values = self.values
if deep:
values = values.copy()
return self.make_block_same_class(values, ndim=self.ndim) |
replace the to_replace value with value, possible to create new
blocks here this is just a call to putmask. regex is not used here.
It is used in ObjectBlocks. It is here for API compatibility. | def replace(self, to_replace, value, inplace=False, filter=None,
regex=False, convert=True):
"""replace the to_replace value with value, possible to create new
blocks here this is just a call to putmask. regex is not used here.
It is used in ObjectBlocks. It is here for API compatibility.
"""
inplace = validate_bool_kwarg(inplace, 'inplace')
original_to_replace = to_replace
# try to replace, if we raise an error, convert to ObjectBlock and
# retry
try:
values, to_replace = self._try_coerce_args(self.values,
to_replace)
mask = missing.mask_missing(values, to_replace)
if filter is not None:
filtered_out = ~self.mgr_locs.isin(filter)
mask[filtered_out.nonzero()[0]] = False
blocks = self.putmask(mask, value, inplace=inplace)
if convert:
blocks = [b.convert(by_item=True, numeric=False,
copy=not inplace) for b in blocks]
return blocks
except (TypeError, ValueError):
# GH 22083, TypeError or ValueError occurred within error handling
# causes infinite loop. Cast and retry only if not objectblock.
if is_object_dtype(self):
raise
# try again with a compatible block
block = self.astype(object)
return block.replace(to_replace=original_to_replace,
value=value,
inplace=inplace,
filter=filter,
regex=regex,
convert=convert) |
Set the value inplace, returning a a maybe different typed block.
Parameters
----------
indexer : tuple, list-like, array-like, slice
The subset of self.values to set
value : object
The value being set
Returns
-------
Block
Notes
-----
`indexer` is a direct slice/positional indexer. `value` must
be a compatible shape. | def setitem(self, indexer, value):
"""Set the value inplace, returning a a maybe different typed block.
Parameters
----------
indexer : tuple, list-like, array-like, slice
The subset of self.values to set
value : object
The value being set
Returns
-------
Block
Notes
-----
`indexer` is a direct slice/positional indexer. `value` must
be a compatible shape.
"""
# coerce None values, if appropriate
if value is None:
if self.is_numeric:
value = np.nan
# coerce if block dtype can store value
values = self.values
try:
values, value = self._try_coerce_args(values, value)
# can keep its own dtype
if hasattr(value, 'dtype') and is_dtype_equal(values.dtype,
value.dtype):
dtype = self.dtype
else:
dtype = 'infer'
except (TypeError, ValueError):
# current dtype cannot store value, coerce to common dtype
find_dtype = False
if hasattr(value, 'dtype'):
dtype = value.dtype
find_dtype = True
elif lib.is_scalar(value):
if isna(value):
# NaN promotion is handled in latter path
dtype = False
else:
dtype, _ = infer_dtype_from_scalar(value,
pandas_dtype=True)
find_dtype = True
else:
dtype = 'infer'
if find_dtype:
dtype = find_common_type([values.dtype, dtype])
if not is_dtype_equal(self.dtype, dtype):
b = self.astype(dtype)
return b.setitem(indexer, value)
# value must be storeable at this moment
arr_value = np.array(value)
# cast the values to a type that can hold nan (if necessary)
if not self._can_hold_element(value):
dtype, _ = maybe_promote(arr_value.dtype)
values = values.astype(dtype)
transf = (lambda x: x.T) if self.ndim == 2 else (lambda x: x)
values = transf(values)
# length checking
check_setitem_lengths(indexer, value, values)
def _is_scalar_indexer(indexer):
# return True if we are all scalar indexers
if arr_value.ndim == 1:
if not isinstance(indexer, tuple):
indexer = tuple([indexer])
return any(isinstance(idx, np.ndarray) and len(idx) == 0
for idx in indexer)
return False
def _is_empty_indexer(indexer):
# return a boolean if we have an empty indexer
if is_list_like(indexer) and not len(indexer):
return True
if arr_value.ndim == 1:
if not isinstance(indexer, tuple):
indexer = tuple([indexer])
return any(isinstance(idx, np.ndarray) and len(idx) == 0
for idx in indexer)
return False
# empty indexers
# 8669 (empty)
if _is_empty_indexer(indexer):
pass
# setting a single element for each dim and with a rhs that could
# be say a list
# GH 6043
elif _is_scalar_indexer(indexer):
values[indexer] = value
# if we are an exact match (ex-broadcasting),
# then use the resultant dtype
elif (len(arr_value.shape) and
arr_value.shape[0] == values.shape[0] and
np.prod(arr_value.shape) == np.prod(values.shape)):
values[indexer] = value
try:
values = values.astype(arr_value.dtype)
except ValueError:
pass
# set
else:
values[indexer] = value
# coerce and try to infer the dtypes of the result
values = self._try_coerce_and_cast_result(values, dtype)
block = self.make_block(transf(values))
return block |
putmask the data to the block; it is possible that we may create a
new dtype of block
return the resulting block(s)
Parameters
----------
mask : the condition to respect
new : a ndarray/object
align : boolean, perform alignment on other/cond, default is True
inplace : perform inplace modification, default is False
axis : int
transpose : boolean
Set to True if self is stored with axes reversed
Returns
-------
a list of new blocks, the result of the putmask | def putmask(self, mask, new, align=True, inplace=False, axis=0,
transpose=False):
""" putmask the data to the block; it is possible that we may create a
new dtype of block
return the resulting block(s)
Parameters
----------
mask : the condition to respect
new : a ndarray/object
align : boolean, perform alignment on other/cond, default is True
inplace : perform inplace modification, default is False
axis : int
transpose : boolean
Set to True if self is stored with axes reversed
Returns
-------
a list of new blocks, the result of the putmask
"""
new_values = self.values if inplace else self.values.copy()
new = getattr(new, 'values', new)
mask = getattr(mask, 'values', mask)
# if we are passed a scalar None, convert it here
if not is_list_like(new) and isna(new) and not self.is_object:
new = self.fill_value
if self._can_hold_element(new):
_, new = self._try_coerce_args(new_values, new)
if transpose:
new_values = new_values.T
# If the default repeat behavior in np.putmask would go in the
# wrong direction, then explicitly repeat and reshape new instead
if getattr(new, 'ndim', 0) >= 1:
if self.ndim - 1 == new.ndim and axis == 1:
new = np.repeat(
new, new_values.shape[-1]).reshape(self.shape)
new = new.astype(new_values.dtype)
# we require exact matches between the len of the
# values we are setting (or is compat). np.putmask
# doesn't check this and will simply truncate / pad
# the output, but we want sane error messages
#
# TODO: this prob needs some better checking
# for 2D cases
if ((is_list_like(new) and
np.any(mask[mask]) and
getattr(new, 'ndim', 1) == 1)):
if not (mask.shape[-1] == len(new) or
mask[mask].shape[-1] == len(new) or
len(new) == 1):
raise ValueError("cannot assign mismatch "
"length to masked array")
np.putmask(new_values, mask, new)
# maybe upcast me
elif mask.any():
if transpose:
mask = mask.T
if isinstance(new, np.ndarray):
new = new.T
axis = new_values.ndim - axis - 1
# Pseudo-broadcast
if getattr(new, 'ndim', 0) >= 1:
if self.ndim - 1 == new.ndim:
new_shape = list(new.shape)
new_shape.insert(axis, 1)
new = new.reshape(tuple(new_shape))
# operate column-by-column
def f(m, v, i):
if i is None:
# ndim==1 case.
n = new
else:
if isinstance(new, np.ndarray):
n = np.squeeze(new[i % new.shape[0]])
else:
n = np.array(new)
# type of the new block
dtype, _ = maybe_promote(n.dtype)
# we need to explicitly astype here to make a copy
n = n.astype(dtype)
nv = _putmask_smart(v, m, n)
return nv
new_blocks = self.split_and_operate(mask, f, inplace)
return new_blocks
if inplace:
return [self]
if transpose:
new_values = new_values.T
return [self.make_block(new_values)] |
coerce the current block to a dtype compat for other
we will return a block, possibly object, and not raise
we can also safely try to coerce to the same dtype
and will receive the same block | def coerce_to_target_dtype(self, other):
"""
coerce the current block to a dtype compat for other
we will return a block, possibly object, and not raise
we can also safely try to coerce to the same dtype
and will receive the same block
"""
# if we cannot then coerce to object
dtype, _ = infer_dtype_from(other, pandas_dtype=True)
if is_dtype_equal(self.dtype, dtype):
return self
if self.is_bool or is_object_dtype(dtype) or is_bool_dtype(dtype):
# we don't upcast to bool
return self.astype(object)
elif ((self.is_float or self.is_complex) and
(is_integer_dtype(dtype) or is_float_dtype(dtype))):
# don't coerce float/complex to int
return self
elif (self.is_datetime or
is_datetime64_dtype(dtype) or
is_datetime64tz_dtype(dtype)):
# not a datetime
if not ((is_datetime64_dtype(dtype) or
is_datetime64tz_dtype(dtype)) and self.is_datetime):
return self.astype(object)
# don't upcast timezone with different timezone or no timezone
mytz = getattr(self.dtype, 'tz', None)
othertz = getattr(dtype, 'tz', None)
if str(mytz) != str(othertz):
return self.astype(object)
raise AssertionError("possible recursion in "
"coerce_to_target_dtype: {} {}".format(
self, other))
elif (self.is_timedelta or is_timedelta64_dtype(dtype)):
# not a timedelta
if not (is_timedelta64_dtype(dtype) and self.is_timedelta):
return self.astype(object)
raise AssertionError("possible recursion in "
"coerce_to_target_dtype: {} {}".format(
self, other))
try:
return self.astype(dtype)
except (ValueError, TypeError, OverflowError):
pass
return self.astype(object) |
fillna but using the interpolate machinery | def _interpolate_with_fill(self, method='pad', axis=0, inplace=False,
limit=None, fill_value=None, coerce=False,
downcast=None):
""" fillna but using the interpolate machinery """
inplace = validate_bool_kwarg(inplace, 'inplace')
# if we are coercing, then don't force the conversion
# if the block can't hold the type
if coerce:
if not self._can_hold_na:
if inplace:
return [self]
else:
return [self.copy()]
values = self.values if inplace else self.values.copy()
values, fill_value = self._try_coerce_args(values, fill_value)
values = missing.interpolate_2d(values, method=method, axis=axis,
limit=limit, fill_value=fill_value,
dtype=self.dtype)
values = self._try_coerce_result(values)
blocks = [self.make_block_same_class(values, ndim=self.ndim)]
return self._maybe_downcast(blocks, downcast) |
interpolate using scipy wrappers | def _interpolate(self, method=None, index=None, values=None,
fill_value=None, axis=0, limit=None,
limit_direction='forward', limit_area=None,
inplace=False, downcast=None, **kwargs):
""" interpolate using scipy wrappers """
inplace = validate_bool_kwarg(inplace, 'inplace')
data = self.values if inplace else self.values.copy()
# only deal with floats
if not self.is_float:
if not self.is_integer:
return self
data = data.astype(np.float64)
if fill_value is None:
fill_value = self.fill_value
if method in ('krogh', 'piecewise_polynomial', 'pchip'):
if not index.is_monotonic:
raise ValueError("{0} interpolation requires that the "
"index be monotonic.".format(method))
# process 1-d slices in the axis direction
def func(x):
# process a 1-d slice, returning it
# should the axis argument be handled below in apply_along_axis?
# i.e. not an arg to missing.interpolate_1d
return missing.interpolate_1d(index, x, method=method, limit=limit,
limit_direction=limit_direction,
limit_area=limit_area,
fill_value=fill_value,
bounds_error=False, **kwargs)
# interp each column independently
interp_values = np.apply_along_axis(func, axis, data)
blocks = [self.make_block_same_class(interp_values)]
return self._maybe_downcast(blocks, downcast) |
Take values according to indexer and return them as a block.bb | def take_nd(self, indexer, axis, new_mgr_locs=None, fill_tuple=None):
"""
Take values according to indexer and return them as a block.bb
"""
# algos.take_nd dispatches for DatetimeTZBlock, CategoricalBlock
# so need to preserve types
# sparse is treated like an ndarray, but needs .get_values() shaping
values = self.values
if self.is_sparse:
values = self.get_values()
if fill_tuple is None:
fill_value = self.fill_value
new_values = algos.take_nd(values, indexer, axis=axis,
allow_fill=False, fill_value=fill_value)
else:
fill_value = fill_tuple[0]
new_values = algos.take_nd(values, indexer, axis=axis,
allow_fill=True, fill_value=fill_value)
if new_mgr_locs is None:
if axis == 0:
slc = libinternals.indexer_as_slice(indexer)
if slc is not None:
new_mgr_locs = self.mgr_locs[slc]
else:
new_mgr_locs = self.mgr_locs[indexer]
else:
new_mgr_locs = self.mgr_locs
if not is_dtype_equal(new_values.dtype, self.dtype):
return self.make_block(new_values, new_mgr_locs)
else:
return self.make_block_same_class(new_values, new_mgr_locs) |
return block for the diff of the values | def diff(self, n, axis=1):
""" return block for the diff of the values """
new_values = algos.diff(self.values, n, axis=axis)
return [self.make_block(values=new_values)] |
shift the block by periods, possibly upcast | def shift(self, periods, axis=0, fill_value=None):
""" shift the block by periods, possibly upcast """
# convert integer to float if necessary. need to do a lot more than
# that, handle boolean etc also
new_values, fill_value = maybe_upcast(self.values, fill_value)
# make sure array sent to np.roll is c_contiguous
f_ordered = new_values.flags.f_contiguous
if f_ordered:
new_values = new_values.T
axis = new_values.ndim - axis - 1
if np.prod(new_values.shape):
new_values = np.roll(new_values, ensure_platform_int(periods),
axis=axis)
axis_indexer = [slice(None)] * self.ndim
if periods > 0:
axis_indexer[axis] = slice(None, periods)
else:
axis_indexer[axis] = slice(periods, None)
new_values[tuple(axis_indexer)] = fill_value
# restore original order
if f_ordered:
new_values = new_values.T
return [self.make_block(new_values)] |
evaluate the block; return result block(s) from the result
Parameters
----------
other : a ndarray/object
cond : the condition to respect
align : boolean, perform alignment on other/cond
errors : str, {'raise', 'ignore'}, default 'raise'
- ``raise`` : allow exceptions to be raised
- ``ignore`` : suppress exceptions. On error return original object
axis : int
transpose : boolean
Set to True if self is stored with axes reversed
Returns
-------
a new block(s), the result of the func | def where(self, other, cond, align=True, errors='raise',
try_cast=False, axis=0, transpose=False):
"""
evaluate the block; return result block(s) from the result
Parameters
----------
other : a ndarray/object
cond : the condition to respect
align : boolean, perform alignment on other/cond
errors : str, {'raise', 'ignore'}, default 'raise'
- ``raise`` : allow exceptions to be raised
- ``ignore`` : suppress exceptions. On error return original object
axis : int
transpose : boolean
Set to True if self is stored with axes reversed
Returns
-------
a new block(s), the result of the func
"""
import pandas.core.computation.expressions as expressions
assert errors in ['raise', 'ignore']
values = self.values
orig_other = other
if transpose:
values = values.T
other = getattr(other, '_values', getattr(other, 'values', other))
cond = getattr(cond, 'values', cond)
# If the default broadcasting would go in the wrong direction, then
# explicitly reshape other instead
if getattr(other, 'ndim', 0) >= 1:
if values.ndim - 1 == other.ndim and axis == 1:
other = other.reshape(tuple(other.shape + (1, )))
elif transpose and values.ndim == self.ndim - 1:
cond = cond.T
if not hasattr(cond, 'shape'):
raise ValueError("where must have a condition that is ndarray "
"like")
# our where function
def func(cond, values, other):
if cond.ravel().all():
return values
values, other = self._try_coerce_args(values, other)
try:
return self._try_coerce_result(expressions.where(
cond, values, other))
except Exception as detail:
if errors == 'raise':
raise TypeError(
'Could not operate [{other!r}] with block values '
'[{detail!s}]'.format(other=other, detail=detail))
else:
# return the values
result = np.empty(values.shape, dtype='float64')
result.fill(np.nan)
return result
# see if we can operate on the entire block, or need item-by-item
# or if we are a single block (ndim == 1)
try:
result = func(cond, values, other)
except TypeError:
# we cannot coerce, return a compat dtype
# we are explicitly ignoring errors
block = self.coerce_to_target_dtype(other)
blocks = block.where(orig_other, cond, align=align,
errors=errors,
try_cast=try_cast, axis=axis,
transpose=transpose)
return self._maybe_downcast(blocks, 'infer')
if self._can_hold_na or self.ndim == 1:
if transpose:
result = result.T
# try to cast if requested
if try_cast:
result = self._try_cast_result(result)
return self.make_block(result)
# might need to separate out blocks
axis = cond.ndim - 1
cond = cond.swapaxes(axis, 0)
mask = np.array([cond[i].all() for i in range(cond.shape[0])],
dtype=bool)
result_blocks = []
for m in [mask, ~mask]:
if m.any():
r = self._try_cast_result(result.take(m.nonzero()[0],
axis=axis))
result_blocks.append(
self.make_block(r.T, placement=self.mgr_locs[m]))
return result_blocks |
Return a list of unstacked blocks of self
Parameters
----------
unstacker_func : callable
Partially applied unstacker.
new_columns : Index
All columns of the unstacked BlockManager.
n_rows : int
Only used in ExtensionBlock.unstack
fill_value : int
Only used in ExtensionBlock.unstack
Returns
-------
blocks : list of Block
New blocks of unstacked values.
mask : array_like of bool
The mask of columns of `blocks` we should keep. | def _unstack(self, unstacker_func, new_columns, n_rows, fill_value):
"""Return a list of unstacked blocks of self
Parameters
----------
unstacker_func : callable
Partially applied unstacker.
new_columns : Index
All columns of the unstacked BlockManager.
n_rows : int
Only used in ExtensionBlock.unstack
fill_value : int
Only used in ExtensionBlock.unstack
Returns
-------
blocks : list of Block
New blocks of unstacked values.
mask : array_like of bool
The mask of columns of `blocks` we should keep.
"""
unstacker = unstacker_func(self.values.T)
new_items = unstacker.get_new_columns()
new_placement = new_columns.get_indexer(new_items)
new_values, mask = unstacker.get_new_values()
mask = mask.any(0)
new_values = new_values.T[mask]
new_placement = new_placement[mask]
blocks = [make_block(new_values, placement=new_placement)]
return blocks, mask |
compute the quantiles of the
Parameters
----------
qs: a scalar or list of the quantiles to be computed
interpolation: type of interpolation, default 'linear'
axis: axis to compute, default 0
Returns
-------
Block | def quantile(self, qs, interpolation='linear', axis=0):
"""
compute the quantiles of the
Parameters
----------
qs: a scalar or list of the quantiles to be computed
interpolation: type of interpolation, default 'linear'
axis: axis to compute, default 0
Returns
-------
Block
"""
if self.is_datetimetz:
# TODO: cleanup this special case.
# We need to operate on i8 values for datetimetz
# but `Block.get_values()` returns an ndarray of objects
# right now. We need an API for "values to do numeric-like ops on"
values = self.values.asi8
# TODO: NonConsolidatableMixin shape
# Usual shape inconsistencies for ExtensionBlocks
if self.ndim > 1:
values = values[None, :]
else:
values = self.get_values()
values, _ = self._try_coerce_args(values, values)
is_empty = values.shape[axis] == 0
orig_scalar = not is_list_like(qs)
if orig_scalar:
# make list-like, unpack later
qs = [qs]
if is_empty:
if self.ndim == 1:
result = self._na_value
else:
# create the array of na_values
# 2d len(values) * len(qs)
result = np.repeat(np.array([self.fill_value] * len(qs)),
len(values)).reshape(len(values),
len(qs))
else:
# asarray needed for Sparse, see GH#24600
# TODO: Why self.values and not values?
mask = np.asarray(isna(self.values))
result = nanpercentile(values, np.array(qs) * 100,
axis=axis, na_value=self.fill_value,
mask=mask, ndim=self.ndim,
interpolation=interpolation)
result = np.array(result, copy=False)
if self.ndim > 1:
result = result.T
if orig_scalar and not lib.is_scalar(result):
# result could be scalar in case with is_empty and self.ndim == 1
assert result.shape[-1] == 1, result.shape
result = result[..., 0]
result = lib.item_from_zerodim(result)
ndim = getattr(result, 'ndim', None) or 0
result = self._try_coerce_result(result)
return make_block(result,
placement=np.arange(len(result)),
ndim=ndim) |
Replace value corresponding to the given boolean array with another
value.
Parameters
----------
to_replace : object or pattern
Scalar to replace or regular expression to match.
value : object
Replacement object.
inplace : bool, default False
Perform inplace modification.
regex : bool, default False
If true, perform regular expression substitution.
convert : bool, default True
If true, try to coerce any object types to better types.
mask : array-like of bool, optional
True indicate corresponding element is ignored.
Returns
-------
A new block if there is anything to replace or the original block. | def _replace_coerce(self, to_replace, value, inplace=True, regex=False,
convert=False, mask=None):
"""
Replace value corresponding to the given boolean array with another
value.
Parameters
----------
to_replace : object or pattern
Scalar to replace or regular expression to match.
value : object
Replacement object.
inplace : bool, default False
Perform inplace modification.
regex : bool, default False
If true, perform regular expression substitution.
convert : bool, default True
If true, try to coerce any object types to better types.
mask : array-like of bool, optional
True indicate corresponding element is ignored.
Returns
-------
A new block if there is anything to replace or the original block.
"""
if mask.any():
if not regex:
self = self.coerce_to_target_dtype(value)
return self.putmask(mask, value, inplace=inplace)
else:
return self._replace_single(to_replace, value, inplace=inplace,
regex=regex,
convert=convert,
mask=mask)
return self |
putmask the data to the block; we must be a single block and not
generate other blocks
return the resulting block
Parameters
----------
mask : the condition to respect
new : a ndarray/object
align : boolean, perform alignment on other/cond, default is True
inplace : perform inplace modification, default is False
Returns
-------
a new block, the result of the putmask | def putmask(self, mask, new, align=True, inplace=False, axis=0,
transpose=False):
"""
putmask the data to the block; we must be a single block and not
generate other blocks
return the resulting block
Parameters
----------
mask : the condition to respect
new : a ndarray/object
align : boolean, perform alignment on other/cond, default is True
inplace : perform inplace modification, default is False
Returns
-------
a new block, the result of the putmask
"""
inplace = validate_bool_kwarg(inplace, 'inplace')
# use block's copy logic.
# .values may be an Index which does shallow copy by default
new_values = self.values if inplace else self.copy().values
new_values, new = self._try_coerce_args(new_values, new)
if isinstance(new, np.ndarray) and len(new) == len(mask):
new = new[mask]
mask = _safe_reshape(mask, new_values.shape)
new_values[mask] = new
new_values = self._try_coerce_result(new_values)
return [self.make_block(values=new_values)] |
Get the placement, values, and mask for a Block unstack.
This is shared between ObjectBlock and ExtensionBlock. They
differ in that ObjectBlock passes the values, while ExtensionBlock
passes the dummy ndarray of positions to be used by a take
later.
Parameters
----------
unstacker : pandas.core.reshape.reshape._Unstacker
new_columns : Index
All columns of the unstacked BlockManager.
Returns
-------
new_placement : ndarray[int]
The placement of the new columns in `new_columns`.
new_values : Union[ndarray, ExtensionArray]
The first return value from _Unstacker.get_new_values.
mask : ndarray[bool]
The second return value from _Unstacker.get_new_values. | def _get_unstack_items(self, unstacker, new_columns):
"""
Get the placement, values, and mask for a Block unstack.
This is shared between ObjectBlock and ExtensionBlock. They
differ in that ObjectBlock passes the values, while ExtensionBlock
passes the dummy ndarray of positions to be used by a take
later.
Parameters
----------
unstacker : pandas.core.reshape.reshape._Unstacker
new_columns : Index
All columns of the unstacked BlockManager.
Returns
-------
new_placement : ndarray[int]
The placement of the new columns in `new_columns`.
new_values : Union[ndarray, ExtensionArray]
The first return value from _Unstacker.get_new_values.
mask : ndarray[bool]
The second return value from _Unstacker.get_new_values.
"""
# shared with ExtensionBlock
new_items = unstacker.get_new_columns()
new_placement = new_columns.get_indexer(new_items)
new_values, mask = unstacker.get_new_values()
mask = mask.any(0)
return new_placement, new_values, mask |
Unbox to an extension array.
This will unbox an ExtensionArray stored in an Index or Series.
ExtensionArrays pass through. No dtype coercion is done.
Parameters
----------
values : Index, Series, ExtensionArray
Returns
-------
ExtensionArray | def _maybe_coerce_values(self, values):
"""Unbox to an extension array.
This will unbox an ExtensionArray stored in an Index or Series.
ExtensionArrays pass through. No dtype coercion is done.
Parameters
----------
values : Index, Series, ExtensionArray
Returns
-------
ExtensionArray
"""
if isinstance(values, (ABCIndexClass, ABCSeries)):
values = values._values
return values |
Set the value inplace, returning a same-typed block.
This differs from Block.setitem by not allowing setitem to change
the dtype of the Block.
Parameters
----------
indexer : tuple, list-like, array-like, slice
The subset of self.values to set
value : object
The value being set
Returns
-------
Block
Notes
-----
`indexer` is a direct slice/positional indexer. `value` must
be a compatible shape. | def setitem(self, indexer, value):
"""Set the value inplace, returning a same-typed block.
This differs from Block.setitem by not allowing setitem to change
the dtype of the Block.
Parameters
----------
indexer : tuple, list-like, array-like, slice
The subset of self.values to set
value : object
The value being set
Returns
-------
Block
Notes
-----
`indexer` is a direct slice/positional indexer. `value` must
be a compatible shape.
"""
if isinstance(indexer, tuple):
# we are always 1-D
indexer = indexer[0]
check_setitem_lengths(indexer, value, self.values)
self.values[indexer] = value
return self |
Take values according to indexer and return them as a block. | def take_nd(self, indexer, axis=0, new_mgr_locs=None, fill_tuple=None):
"""
Take values according to indexer and return them as a block.
"""
if fill_tuple is None:
fill_value = None
else:
fill_value = fill_tuple[0]
# axis doesn't matter; we are really a single-dim object
# but are passed the axis depending on the calling routing
# if its REALLY axis 0, then this will be a reindex and not a take
new_values = self.values.take(indexer, fill_value=fill_value,
allow_fill=True)
if self.ndim == 1 and new_mgr_locs is None:
new_mgr_locs = [0]
else:
if new_mgr_locs is None:
new_mgr_locs = self.mgr_locs
return self.make_block_same_class(new_values, new_mgr_locs) |
return a slice of my values | def _slice(self, slicer):
""" return a slice of my values """
# slice the category
# return same dims as we currently have
if isinstance(slicer, tuple) and len(slicer) == 2:
if not com.is_null_slice(slicer[0]):
raise AssertionError("invalid slicing for a 1-ndim "
"categorical")
slicer = slicer[1]
return self.values[slicer] |
Concatenate list of single blocks of the same type. | def concat_same_type(self, to_concat, placement=None):
"""
Concatenate list of single blocks of the same type.
"""
values = self._holder._concat_same_type(
[blk.values for blk in to_concat])
placement = placement or slice(0, len(values), 1)
return self.make_block_same_class(values, ndim=self.ndim,
placement=placement) |
Shift the block by `periods`.
Dispatches to underlying ExtensionArray and re-boxes in an
ExtensionBlock. | def shift(self,
periods: int,
axis: libinternals.BlockPlacement = 0,
fill_value: Any = None) -> List['ExtensionBlock']:
"""
Shift the block by `periods`.
Dispatches to underlying ExtensionArray and re-boxes in an
ExtensionBlock.
"""
return [
self.make_block_same_class(
self.values.shift(periods=periods, fill_value=fill_value),
placement=self.mgr_locs, ndim=self.ndim)
] |
convert to our native types format, slicing if desired | def to_native_types(self, slicer=None, na_rep='', float_format=None,
decimal='.', quoting=None, **kwargs):
""" convert to our native types format, slicing if desired """
values = self.values
if slicer is not None:
values = values[:, slicer]
# see gh-13418: no special formatting is desired at the
# output (important for appropriate 'quoting' behaviour),
# so do not pass it through the FloatArrayFormatter
if float_format is None and decimal == '.':
mask = isna(values)
if not quoting:
values = values.astype(str)
else:
values = np.array(values, dtype='object')
values[mask] = na_rep
return values
from pandas.io.formats.format import FloatArrayFormatter
formatter = FloatArrayFormatter(values, na_rep=na_rep,
float_format=float_format,
decimal=decimal, quoting=quoting,
fixed_width=False)
return formatter.get_result_as_array() |
return object dtype as boxed values, such as Timestamps/Timedelta | def get_values(self, dtype=None):
"""
return object dtype as boxed values, such as Timestamps/Timedelta
"""
if is_object_dtype(dtype):
values = self.values.ravel()
result = self._holder(values).astype(object)
return result.reshape(self.values.shape)
return self.values |
Input validation for values passed to __init__. Ensure that
we have datetime64ns, coercing if necessary.
Parameters
----------
values : array-like
Must be convertible to datetime64
Returns
-------
values : ndarray[datetime64ns]
Overridden by DatetimeTZBlock. | def _maybe_coerce_values(self, values):
"""Input validation for values passed to __init__. Ensure that
we have datetime64ns, coercing if necessary.
Parameters
----------
values : array-like
Must be convertible to datetime64
Returns
-------
values : ndarray[datetime64ns]
Overridden by DatetimeTZBlock.
"""
if values.dtype != _NS_DTYPE:
values = conversion.ensure_datetime64ns(values)
if isinstance(values, DatetimeArray):
values = values._data
assert isinstance(values, np.ndarray), type(values)
return values |
these automatically copy, so copy=True has no effect
raise on an except if raise == True | def _astype(self, dtype, **kwargs):
"""
these automatically copy, so copy=True has no effect
raise on an except if raise == True
"""
dtype = pandas_dtype(dtype)
# if we are passed a datetime64[ns, tz]
if is_datetime64tz_dtype(dtype):
values = self.values
if getattr(values, 'tz', None) is None:
values = DatetimeIndex(values).tz_localize('UTC')
values = values.tz_convert(dtype.tz)
return self.make_block(values)
# delegate
return super()._astype(dtype=dtype, **kwargs) |
Coerce values and other to dtype 'i8'. NaN and NaT convert to
the smallest i8, and will correctly round-trip to NaT if converted
back in _try_coerce_result. values is always ndarray-like, other
may not be
Parameters
----------
values : ndarray-like
other : ndarray-like or scalar
Returns
-------
base-type values, base-type other | def _try_coerce_args(self, values, other):
"""
Coerce values and other to dtype 'i8'. NaN and NaT convert to
the smallest i8, and will correctly round-trip to NaT if converted
back in _try_coerce_result. values is always ndarray-like, other
may not be
Parameters
----------
values : ndarray-like
other : ndarray-like or scalar
Returns
-------
base-type values, base-type other
"""
values = values.view('i8')
if isinstance(other, bool):
raise TypeError
elif is_null_datetimelike(other):
other = tslibs.iNaT
elif isinstance(other, (datetime, np.datetime64, date)):
other = self._box_func(other)
if getattr(other, 'tz') is not None:
raise TypeError("cannot coerce a Timestamp with a tz on a "
"naive Block")
other = other.asm8.view('i8')
elif hasattr(other, 'dtype') and is_datetime64_dtype(other):
other = other.astype('i8', copy=False).view('i8')
else:
# coercion issues
# let higher levels handle
raise TypeError(other)
return values, other |
reverse of try_coerce_args | def _try_coerce_result(self, result):
""" reverse of try_coerce_args """
if isinstance(result, np.ndarray):
if result.dtype.kind in ['i', 'f']:
result = result.astype('M8[ns]')
elif isinstance(result, (np.integer, np.float, np.datetime64)):
result = self._box_func(result)
return result |
convert to our native types format, slicing if desired | def to_native_types(self, slicer=None, na_rep=None, date_format=None,
quoting=None, **kwargs):
""" convert to our native types format, slicing if desired """
values = self.values
i8values = self.values.view('i8')
if slicer is not None:
values = values[..., slicer]
i8values = i8values[..., slicer]
from pandas.io.formats.format import _get_format_datetime64_from_values
fmt = _get_format_datetime64_from_values(values, date_format)
result = tslib.format_array_from_datetime(
i8values.ravel(), tz=getattr(self.values, 'tz', None),
format=fmt, na_rep=na_rep).reshape(i8values.shape)
return np.atleast_2d(result) |
Modify Block in-place with new item value
Returns
-------
None | def set(self, locs, values):
"""
Modify Block in-place with new item value
Returns
-------
None
"""
values = conversion.ensure_datetime64ns(values, copy=False)
self.values[locs] = values |
Input validation for values passed to __init__. Ensure that
we have datetime64TZ, coercing if necessary.
Parametetrs
-----------
values : array-like
Must be convertible to datetime64
Returns
-------
values : DatetimeArray | def _maybe_coerce_values(self, values):
"""Input validation for values passed to __init__. Ensure that
we have datetime64TZ, coercing if necessary.
Parametetrs
-----------
values : array-like
Must be convertible to datetime64
Returns
-------
values : DatetimeArray
"""
if not isinstance(values, self._holder):
values = self._holder(values)
if values.tz is None:
raise ValueError("cannot create a DatetimeTZBlock without a tz")
return values |
Returns an ndarray of values.
Parameters
----------
dtype : np.dtype
Only `object`-like dtypes are respected here (not sure
why).
Returns
-------
values : ndarray
When ``dtype=object``, then and object-dtype ndarray of
boxed values is returned. Otherwise, an M8[ns] ndarray
is returned.
DatetimeArray is always 1-d. ``get_values`` will reshape
the return value to be the same dimensionality as the
block. | def get_values(self, dtype=None):
"""
Returns an ndarray of values.
Parameters
----------
dtype : np.dtype
Only `object`-like dtypes are respected here (not sure
why).
Returns
-------
values : ndarray
When ``dtype=object``, then and object-dtype ndarray of
boxed values is returned. Otherwise, an M8[ns] ndarray
is returned.
DatetimeArray is always 1-d. ``get_values`` will reshape
the return value to be the same dimensionality as the
block.
"""
values = self.values
if is_object_dtype(dtype):
values = values._box_values(values._data)
values = np.asarray(values)
if self.ndim == 2:
# Ensure that our shape is correct for DataFrame.
# ExtensionArrays are always 1-D, even in a DataFrame when
# the analogous NumPy-backed column would be a 2-D ndarray.
values = values.reshape(1, -1)
return values |
return a slice of my values | def _slice(self, slicer):
""" return a slice of my values """
if isinstance(slicer, tuple):
col, loc = slicer
if not com.is_null_slice(col) and col != 0:
raise IndexError("{0} only contains one item".format(self))
return self.values[loc]
return self.values[slicer] |
localize and return i8 for the values
Parameters
----------
values : ndarray-like
other : ndarray-like or scalar
Returns
-------
base-type values, base-type other | def _try_coerce_args(self, values, other):
"""
localize and return i8 for the values
Parameters
----------
values : ndarray-like
other : ndarray-like or scalar
Returns
-------
base-type values, base-type other
"""
# asi8 is a view, needs copy
values = _block_shape(values.view("i8"), ndim=self.ndim)
if isinstance(other, ABCSeries):
other = self._holder(other)
if isinstance(other, bool):
raise TypeError
elif is_datetime64_dtype(other):
# add the tz back
other = self._holder(other, dtype=self.dtype)
elif is_null_datetimelike(other):
other = tslibs.iNaT
elif isinstance(other, self._holder):
if other.tz != self.values.tz:
raise ValueError("incompatible or non tz-aware value")
other = _block_shape(other.asi8, ndim=self.ndim)
elif isinstance(other, (np.datetime64, datetime, date)):
other = tslibs.Timestamp(other)
tz = getattr(other, 'tz', None)
# test we can have an equal time zone
if tz is None or str(tz) != str(self.values.tz):
raise ValueError("incompatible or non tz-aware value")
other = other.value
else:
raise TypeError(other)
return values, other |
reverse of try_coerce_args | def _try_coerce_result(self, result):
""" reverse of try_coerce_args """
if isinstance(result, np.ndarray):
if result.dtype.kind in ['i', 'f']:
result = result.astype('M8[ns]')
elif isinstance(result, (np.integer, np.float, np.datetime64)):
result = self._box_func(result)
if isinstance(result, np.ndarray):
# allow passing of > 1dim if its trivial
if result.ndim > 1:
result = result.reshape(np.prod(result.shape))
# GH#24096 new values invalidates a frequency
result = self._holder._simple_new(result, freq=None,
dtype=self.values.dtype)
return result |
1st discrete difference
Parameters
----------
n : int, number of periods to diff
axis : int, axis to diff upon. default 0
Return
------
A list with a new TimeDeltaBlock.
Note
----
The arguments here are mimicking shift so they are called correctly
by apply. | def diff(self, n, axis=0):
"""1st discrete difference
Parameters
----------
n : int, number of periods to diff
axis : int, axis to diff upon. default 0
Return
------
A list with a new TimeDeltaBlock.
Note
----
The arguments here are mimicking shift so they are called correctly
by apply.
"""
if axis == 0:
# Cannot currently calculate diff across multiple blocks since this
# function is invoked via apply
raise NotImplementedError
new_values = (self.values - self.shift(n, axis=axis)[0].values).asi8
# Reshape the new_values like how algos.diff does for timedelta data
new_values = new_values.reshape(1, len(new_values))
new_values = new_values.astype('timedelta64[ns]')
return [TimeDeltaBlock(new_values, placement=self.mgr_locs.indexer)] |
Coerce values and other to int64, with null values converted to
iNaT. values is always ndarray-like, other may not be
Parameters
----------
values : ndarray-like
other : ndarray-like or scalar
Returns
-------
base-type values, base-type other | def _try_coerce_args(self, values, other):
"""
Coerce values and other to int64, with null values converted to
iNaT. values is always ndarray-like, other may not be
Parameters
----------
values : ndarray-like
other : ndarray-like or scalar
Returns
-------
base-type values, base-type other
"""
values = values.view('i8')
if isinstance(other, bool):
raise TypeError
elif is_null_datetimelike(other):
other = tslibs.iNaT
elif isinstance(other, (timedelta, np.timedelta64)):
other = Timedelta(other).value
elif hasattr(other, 'dtype') and is_timedelta64_dtype(other):
other = other.astype('i8', copy=False).view('i8')
else:
# coercion issues
# let higher levels handle
raise TypeError(other)
return values, other |
reverse of try_coerce_args / try_operate | def _try_coerce_result(self, result):
""" reverse of try_coerce_args / try_operate """
if isinstance(result, np.ndarray):
mask = isna(result)
if result.dtype.kind in ['i', 'f']:
result = result.astype('m8[ns]')
result[mask] = tslibs.iNaT
elif isinstance(result, (np.integer, np.float)):
result = self._box_func(result)
return result |
convert to our native types format, slicing if desired | def to_native_types(self, slicer=None, na_rep=None, quoting=None,
**kwargs):
""" convert to our native types format, slicing if desired """
values = self.values
if slicer is not None:
values = values[:, slicer]
mask = isna(values)
rvalues = np.empty(values.shape, dtype=object)
if na_rep is None:
na_rep = 'NaT'
rvalues[mask] = na_rep
imask = (~mask).ravel()
# FIXME:
# should use the formats.format.Timedelta64Formatter here
# to figure what format to pass to the Timedelta
# e.g. to not show the decimals say
rvalues.flat[imask] = np.array([Timedelta(val)._repr_base(format='all')
for val in values.ravel()[imask]],
dtype=object)
return rvalues |
attempt to coerce any object types to better types return a copy of
the block (if copy = True) by definition we ARE an ObjectBlock!!!!!
can return multiple blocks! | def convert(self, *args, **kwargs):
""" attempt to coerce any object types to better types return a copy of
the block (if copy = True) by definition we ARE an ObjectBlock!!!!!
can return multiple blocks!
"""
if args:
raise NotImplementedError
by_item = kwargs.get('by_item', True)
new_inputs = ['coerce', 'datetime', 'numeric', 'timedelta']
new_style = False
for kw in new_inputs:
new_style |= kw in kwargs
if new_style:
fn = soft_convert_objects
fn_inputs = new_inputs
else:
fn = maybe_convert_objects
fn_inputs = ['convert_dates', 'convert_numeric',
'convert_timedeltas']
fn_inputs += ['copy']
fn_kwargs = {key: kwargs[key] for key in fn_inputs if key in kwargs}
# operate column-by-column
def f(m, v, i):
shape = v.shape
values = fn(v.ravel(), **fn_kwargs)
try:
values = values.reshape(shape)
values = _block_shape(values, ndim=self.ndim)
except (AttributeError, NotImplementedError):
pass
return values
if by_item and not self._is_single_block:
blocks = self.split_and_operate(None, f, False)
else:
values = f(None, self.values.ravel(), None)
blocks = [make_block(values, ndim=self.ndim,
placement=self.mgr_locs)]
return blocks |
Modify Block in-place with new item value
Returns
-------
None | def set(self, locs, values):
"""
Modify Block in-place with new item value
Returns
-------
None
"""
try:
self.values[locs] = values
except (ValueError):
# broadcasting error
# see GH6171
new_shape = list(values.shape)
new_shape[0] = len(self.items)
self.values = np.empty(tuple(new_shape), dtype=self.dtype)
self.values.fill(np.nan)
self.values[locs] = values |
provide coercion to our input arguments | def _try_coerce_args(self, values, other):
""" provide coercion to our input arguments """
if isinstance(other, ABCDatetimeIndex):
# May get a DatetimeIndex here. Unbox it.
other = other.array
if isinstance(other, DatetimeArray):
# hit in pandas/tests/indexing/test_coercion.py
# ::TestWhereCoercion::test_where_series_datetime64[datetime64tz]
# when falling back to ObjectBlock.where
other = other.astype(object)
return values, other |
Replace elements by the given value.
Parameters
----------
to_replace : object or pattern
Scalar to replace or regular expression to match.
value : object
Replacement object.
inplace : bool, default False
Perform inplace modification.
filter : list, optional
regex : bool, default False
If true, perform regular expression substitution.
convert : bool, default True
If true, try to coerce any object types to better types.
mask : array-like of bool, optional
True indicate corresponding element is ignored.
Returns
-------
a new block, the result after replacing | def _replace_single(self, to_replace, value, inplace=False, filter=None,
regex=False, convert=True, mask=None):
"""
Replace elements by the given value.
Parameters
----------
to_replace : object or pattern
Scalar to replace or regular expression to match.
value : object
Replacement object.
inplace : bool, default False
Perform inplace modification.
filter : list, optional
regex : bool, default False
If true, perform regular expression substitution.
convert : bool, default True
If true, try to coerce any object types to better types.
mask : array-like of bool, optional
True indicate corresponding element is ignored.
Returns
-------
a new block, the result after replacing
"""
inplace = validate_bool_kwarg(inplace, 'inplace')
# to_replace is regex compilable
to_rep_re = regex and is_re_compilable(to_replace)
# regex is regex compilable
regex_re = is_re_compilable(regex)
# only one will survive
if to_rep_re and regex_re:
raise AssertionError('only one of to_replace and regex can be '
'regex compilable')
# if regex was passed as something that can be a regex (rather than a
# boolean)
if regex_re:
to_replace = regex
regex = regex_re or to_rep_re
# try to get the pattern attribute (compiled re) or it's a string
try:
pattern = to_replace.pattern
except AttributeError:
pattern = to_replace
# if the pattern is not empty and to_replace is either a string or a
# regex
if regex and pattern:
rx = re.compile(to_replace)
else:
# if the thing to replace is not a string or compiled regex call
# the superclass method -> to_replace is some kind of object
return super().replace(to_replace, value, inplace=inplace,
filter=filter, regex=regex)
new_values = self.values if inplace else self.values.copy()
# deal with replacing values with objects (strings) that match but
# whose replacement is not a string (numeric, nan, object)
if isna(value) or not isinstance(value, str):
def re_replacer(s):
try:
return value if rx.search(s) is not None else s
except TypeError:
return s
else:
# value is guaranteed to be a string here, s can be either a string
# or null if it's null it gets returned
def re_replacer(s):
try:
return rx.sub(value, s)
except TypeError:
return s
f = np.vectorize(re_replacer, otypes=[self.dtype])
if filter is None:
filt = slice(None)
else:
filt = self.mgr_locs.isin(filter).nonzero()[0]
if mask is None:
new_values[filt] = f(new_values[filt])
else:
new_values[filt][mask] = f(new_values[filt][mask])
# convert
block = self.make_block(new_values)
if convert:
block = block.convert(by_item=True, numeric=False)
return block |
Replace value corresponding to the given boolean array with another
value.
Parameters
----------
to_replace : object or pattern
Scalar to replace or regular expression to match.
value : object
Replacement object.
inplace : bool, default False
Perform inplace modification.
regex : bool, default False
If true, perform regular expression substitution.
convert : bool, default True
If true, try to coerce any object types to better types.
mask : array-like of bool, optional
True indicate corresponding element is ignored.
Returns
-------
A new block if there is anything to replace or the original block. | def _replace_coerce(self, to_replace, value, inplace=True, regex=False,
convert=False, mask=None):
"""
Replace value corresponding to the given boolean array with another
value.
Parameters
----------
to_replace : object or pattern
Scalar to replace or regular expression to match.
value : object
Replacement object.
inplace : bool, default False
Perform inplace modification.
regex : bool, default False
If true, perform regular expression substitution.
convert : bool, default True
If true, try to coerce any object types to better types.
mask : array-like of bool, optional
True indicate corresponding element is ignored.
Returns
-------
A new block if there is anything to replace or the original block.
"""
if mask.any():
block = super()._replace_coerce(
to_replace=to_replace, value=value, inplace=inplace,
regex=regex, convert=convert, mask=mask)
if convert:
block = [b.convert(by_item=True, numeric=False, copy=True)
for b in block]
return block
return self |
reverse of try_coerce_args | def _try_coerce_result(self, result):
""" reverse of try_coerce_args """
# GH12564: CategoricalBlock is 1-dim only
# while returned results could be any dim
if ((not is_categorical_dtype(result)) and
isinstance(result, np.ndarray)):
result = _block_shape(result, ndim=self.ndim)
return result |
convert to our native types format, slicing if desired | def to_native_types(self, slicer=None, na_rep='', quoting=None, **kwargs):
""" convert to our native types format, slicing if desired """
values = self.values
if slicer is not None:
# Categorical is always one dimension
values = values[slicer]
mask = isna(values)
values = np.array(values, dtype='object')
values[mask] = na_rep
# we are expected to return a 2-d ndarray
return values.reshape(1, len(values)) |
helper which recursively generate an xlwt easy style string
for example:
hstyle = {"font": {"bold": True},
"border": {"top": "thin",
"right": "thin",
"bottom": "thin",
"left": "thin"},
"align": {"horiz": "center"}}
will be converted to
font: bold on; \
border: top thin, right thin, bottom thin, left thin; \
align: horiz center; | def _style_to_xlwt(cls, item, firstlevel=True, field_sep=',',
line_sep=';'):
"""helper which recursively generate an xlwt easy style string
for example:
hstyle = {"font": {"bold": True},
"border": {"top": "thin",
"right": "thin",
"bottom": "thin",
"left": "thin"},
"align": {"horiz": "center"}}
will be converted to
font: bold on; \
border: top thin, right thin, bottom thin, left thin; \
align: horiz center;
"""
if hasattr(item, 'items'):
if firstlevel:
it = ["{key}: {val}"
.format(key=key, val=cls._style_to_xlwt(value, False))
for key, value in item.items()]
out = "{sep} ".format(sep=(line_sep).join(it))
return out
else:
it = ["{key} {val}"
.format(key=key, val=cls._style_to_xlwt(value, False))
for key, value in item.items()]
out = "{sep} ".format(sep=(field_sep).join(it))
return out
else:
item = "{item}".format(item=item)
item = item.replace("True", "on")
item = item.replace("False", "off")
return item |
converts a style_dict to an xlwt style object
Parameters
----------
style_dict : style dictionary to convert
num_format_str : optional number format string | def _convert_to_style(cls, style_dict, num_format_str=None):
"""
converts a style_dict to an xlwt style object
Parameters
----------
style_dict : style dictionary to convert
num_format_str : optional number format string
"""
import xlwt
if style_dict:
xlwt_stylestr = cls._style_to_xlwt(style_dict)
style = xlwt.easyxf(xlwt_stylestr, field_sep=',', line_sep=';')
else:
style = xlwt.XFStyle()
if num_format_str is not None:
style.num_format_str = num_format_str
return style |
converts a style_dict to an xlsxwriter format dict
Parameters
----------
style_dict : style dictionary to convert
num_format_str : optional number format string | def convert(cls, style_dict, num_format_str=None):
"""
converts a style_dict to an xlsxwriter format dict
Parameters
----------
style_dict : style dictionary to convert
num_format_str : optional number format string
"""
# Create a XlsxWriter format object.
props = {}
if num_format_str is not None:
props['num_format'] = num_format_str
if style_dict is None:
return props
if 'borders' in style_dict:
style_dict = style_dict.copy()
style_dict['border'] = style_dict.pop('borders')
for style_group_key, style_group in style_dict.items():
for src, dst in cls.STYLE_MAPPING.get(style_group_key, []):
# src is a sequence of keys into a nested dict
# dst is a flat key
if dst in props:
continue
v = style_group
for k in src:
try:
v = v[k]
except (KeyError, TypeError):
break
else:
props[dst] = v
if isinstance(props.get('pattern'), str):
# TODO: support other fill patterns
props['pattern'] = 0 if props['pattern'] == 'none' else 1
for k in ['border', 'top', 'right', 'bottom', 'left']:
if isinstance(props.get(k), str):
try:
props[k] = ['none', 'thin', 'medium', 'dashed', 'dotted',
'thick', 'double', 'hair', 'mediumDashed',
'dashDot', 'mediumDashDot', 'dashDotDot',
'mediumDashDotDot',
'slantDashDot'].index(props[k])
except ValueError:
props[k] = 2
if isinstance(props.get('font_script'), str):
props['font_script'] = ['baseline', 'superscript',
'subscript'].index(props['font_script'])
if isinstance(props.get('underline'), str):
props['underline'] = {'none': 0, 'single': 1, 'double': 2,
'singleAccounting': 33,
'doubleAccounting': 34}[props['underline']]
return props |
Unstack an ExtensionArray-backed Series.
The ExtensionDtype is preserved.
Parameters
----------
series : Series
A Series with an ExtensionArray for values
level : Any
The level name or number.
fill_value : Any
The user-level (not physical storage) fill value to use for
missing values introduced by the reshape. Passed to
``series.values.take``.
Returns
-------
DataFrame
Each column of the DataFrame will have the same dtype as
the input Series. | def _unstack_extension_series(series, level, fill_value):
"""
Unstack an ExtensionArray-backed Series.
The ExtensionDtype is preserved.
Parameters
----------
series : Series
A Series with an ExtensionArray for values
level : Any
The level name or number.
fill_value : Any
The user-level (not physical storage) fill value to use for
missing values introduced by the reshape. Passed to
``series.values.take``.
Returns
-------
DataFrame
Each column of the DataFrame will have the same dtype as
the input Series.
"""
# Implementation note: the basic idea is to
# 1. Do a regular unstack on a dummy array of integers
# 2. Followup with a columnwise take.
# We use the dummy take to discover newly-created missing values
# introduced by the reshape.
from pandas.core.reshape.concat import concat
dummy_arr = np.arange(len(series))
# fill_value=-1, since we will do a series.values.take later
result = _Unstacker(dummy_arr, series.index,
level=level, fill_value=-1).get_result()
out = []
values = extract_array(series, extract_numpy=False)
for col, indices in result.iteritems():
out.append(Series(values.take(indices.values,
allow_fill=True,
fill_value=fill_value),
name=col, index=result.index))
return concat(out, axis='columns', copy=False, keys=result.columns) |
Convert DataFrame to Series with multi-level Index. Columns become the
second level of the resulting hierarchical index
Returns
-------
stacked : Series | def stack(frame, level=-1, dropna=True):
"""
Convert DataFrame to Series with multi-level Index. Columns become the
second level of the resulting hierarchical index
Returns
-------
stacked : Series
"""
def factorize(index):
if index.is_unique:
return index, np.arange(len(index))
codes, categories = _factorize_from_iterable(index)
return categories, codes
N, K = frame.shape
# Will also convert negative level numbers and check if out of bounds.
level_num = frame.columns._get_level_number(level)
if isinstance(frame.columns, MultiIndex):
return _stack_multi_columns(frame, level_num=level_num, dropna=dropna)
elif isinstance(frame.index, MultiIndex):
new_levels = list(frame.index.levels)
new_codes = [lab.repeat(K) for lab in frame.index.codes]
clev, clab = factorize(frame.columns)
new_levels.append(clev)
new_codes.append(np.tile(clab, N).ravel())
new_names = list(frame.index.names)
new_names.append(frame.columns.name)
new_index = MultiIndex(levels=new_levels, codes=new_codes,
names=new_names, verify_integrity=False)
else:
levels, (ilab, clab) = zip(*map(factorize, (frame.index,
frame.columns)))
codes = ilab.repeat(K), np.tile(clab, N).ravel()
new_index = MultiIndex(levels=levels, codes=codes,
names=[frame.index.name, frame.columns.name],
verify_integrity=False)
if frame._is_homogeneous_type:
# For homogeneous EAs, frame.values will coerce to object. So
# we concatenate instead.
dtypes = list(frame.dtypes.values)
dtype = dtypes[0]
if is_extension_array_dtype(dtype):
arr = dtype.construct_array_type()
new_values = arr._concat_same_type([
col._values for _, col in frame.iteritems()
])
new_values = _reorder_for_extension_array_stack(new_values, N, K)
else:
# homogeneous, non-EA
new_values = frame.values.ravel()
else:
# non-homogeneous
new_values = frame.values.ravel()
if dropna:
mask = notna(new_values)
new_values = new_values[mask]
new_index = new_index[mask]
return frame._constructor_sliced(new_values, index=new_index) |
Convert categorical variable into dummy/indicator variables.
Parameters
----------
data : array-like, Series, or DataFrame
Data of which to get dummy indicators.
prefix : str, list of str, or dict of str, default None
String to append DataFrame column names.
Pass a list with length equal to the number of columns
when calling get_dummies on a DataFrame. Alternatively, `prefix`
can be a dictionary mapping column names to prefixes.
prefix_sep : str, default '_'
If appending prefix, separator/delimiter to use. Or pass a
list or dictionary as with `prefix`.
dummy_na : bool, default False
Add a column to indicate NaNs, if False NaNs are ignored.
columns : list-like, default None
Column names in the DataFrame to be encoded.
If `columns` is None then all the columns with
`object` or `category` dtype will be converted.
sparse : bool, default False
Whether the dummy-encoded columns should be backed by
a :class:`SparseArray` (True) or a regular NumPy array (False).
drop_first : bool, default False
Whether to get k-1 dummies out of k categorical levels by removing the
first level.
.. versionadded:: 0.18.0
dtype : dtype, default np.uint8
Data type for new columns. Only a single dtype is allowed.
.. versionadded:: 0.23.0
Returns
-------
DataFrame
Dummy-coded data.
See Also
--------
Series.str.get_dummies : Convert Series to dummy codes.
Examples
--------
>>> s = pd.Series(list('abca'))
>>> pd.get_dummies(s)
a b c
0 1 0 0
1 0 1 0
2 0 0 1
3 1 0 0
>>> s1 = ['a', 'b', np.nan]
>>> pd.get_dummies(s1)
a b
0 1 0
1 0 1
2 0 0
>>> pd.get_dummies(s1, dummy_na=True)
a b NaN
0 1 0 0
1 0 1 0
2 0 0 1
>>> df = pd.DataFrame({'A': ['a', 'b', 'a'], 'B': ['b', 'a', 'c'],
... 'C': [1, 2, 3]})
>>> pd.get_dummies(df, prefix=['col1', 'col2'])
C col1_a col1_b col2_a col2_b col2_c
0 1 1 0 0 1 0
1 2 0 1 1 0 0
2 3 1 0 0 0 1
>>> pd.get_dummies(pd.Series(list('abcaa')))
a b c
0 1 0 0
1 0 1 0
2 0 0 1
3 1 0 0
4 1 0 0
>>> pd.get_dummies(pd.Series(list('abcaa')), drop_first=True)
b c
0 0 0
1 1 0
2 0 1
3 0 0
4 0 0
>>> pd.get_dummies(pd.Series(list('abc')), dtype=float)
a b c
0 1.0 0.0 0.0
1 0.0 1.0 0.0
2 0.0 0.0 1.0 | def get_dummies(data, prefix=None, prefix_sep='_', dummy_na=False,
columns=None, sparse=False, drop_first=False, dtype=None):
"""
Convert categorical variable into dummy/indicator variables.
Parameters
----------
data : array-like, Series, or DataFrame
Data of which to get dummy indicators.
prefix : str, list of str, or dict of str, default None
String to append DataFrame column names.
Pass a list with length equal to the number of columns
when calling get_dummies on a DataFrame. Alternatively, `prefix`
can be a dictionary mapping column names to prefixes.
prefix_sep : str, default '_'
If appending prefix, separator/delimiter to use. Or pass a
list or dictionary as with `prefix`.
dummy_na : bool, default False
Add a column to indicate NaNs, if False NaNs are ignored.
columns : list-like, default None
Column names in the DataFrame to be encoded.
If `columns` is None then all the columns with
`object` or `category` dtype will be converted.
sparse : bool, default False
Whether the dummy-encoded columns should be backed by
a :class:`SparseArray` (True) or a regular NumPy array (False).
drop_first : bool, default False
Whether to get k-1 dummies out of k categorical levels by removing the
first level.
.. versionadded:: 0.18.0
dtype : dtype, default np.uint8
Data type for new columns. Only a single dtype is allowed.
.. versionadded:: 0.23.0
Returns
-------
DataFrame
Dummy-coded data.
See Also
--------
Series.str.get_dummies : Convert Series to dummy codes.
Examples
--------
>>> s = pd.Series(list('abca'))
>>> pd.get_dummies(s)
a b c
0 1 0 0
1 0 1 0
2 0 0 1
3 1 0 0
>>> s1 = ['a', 'b', np.nan]
>>> pd.get_dummies(s1)
a b
0 1 0
1 0 1
2 0 0
>>> pd.get_dummies(s1, dummy_na=True)
a b NaN
0 1 0 0
1 0 1 0
2 0 0 1
>>> df = pd.DataFrame({'A': ['a', 'b', 'a'], 'B': ['b', 'a', 'c'],
... 'C': [1, 2, 3]})
>>> pd.get_dummies(df, prefix=['col1', 'col2'])
C col1_a col1_b col2_a col2_b col2_c
0 1 1 0 0 1 0
1 2 0 1 1 0 0
2 3 1 0 0 0 1
>>> pd.get_dummies(pd.Series(list('abcaa')))
a b c
0 1 0 0
1 0 1 0
2 0 0 1
3 1 0 0
4 1 0 0
>>> pd.get_dummies(pd.Series(list('abcaa')), drop_first=True)
b c
0 0 0
1 1 0
2 0 1
3 0 0
4 0 0
>>> pd.get_dummies(pd.Series(list('abc')), dtype=float)
a b c
0 1.0 0.0 0.0
1 0.0 1.0 0.0
2 0.0 0.0 1.0
"""
from pandas.core.reshape.concat import concat
from itertools import cycle
dtypes_to_encode = ['object', 'category']
if isinstance(data, DataFrame):
# determine columns being encoded
if columns is None:
data_to_encode = data.select_dtypes(
include=dtypes_to_encode)
else:
data_to_encode = data[columns]
# validate prefixes and separator to avoid silently dropping cols
def check_len(item, name):
len_msg = ("Length of '{name}' ({len_item}) did not match the "
"length of the columns being encoded ({len_enc}).")
if is_list_like(item):
if not len(item) == data_to_encode.shape[1]:
len_msg = len_msg.format(name=name, len_item=len(item),
len_enc=data_to_encode.shape[1])
raise ValueError(len_msg)
check_len(prefix, 'prefix')
check_len(prefix_sep, 'prefix_sep')
if isinstance(prefix, str):
prefix = cycle([prefix])
if isinstance(prefix, dict):
prefix = [prefix[col] for col in data_to_encode.columns]
if prefix is None:
prefix = data_to_encode.columns
# validate separators
if isinstance(prefix_sep, str):
prefix_sep = cycle([prefix_sep])
elif isinstance(prefix_sep, dict):
prefix_sep = [prefix_sep[col] for col in data_to_encode.columns]
if data_to_encode.shape == data.shape:
# Encoding the entire df, do not prepend any dropped columns
with_dummies = []
elif columns is not None:
# Encoding only cols specified in columns. Get all cols not in
# columns to prepend to result.
with_dummies = [data.drop(columns, axis=1)]
else:
# Encoding only object and category dtype columns. Get remaining
# columns to prepend to result.
with_dummies = [data.select_dtypes(exclude=dtypes_to_encode)]
for (col, pre, sep) in zip(data_to_encode.iteritems(), prefix,
prefix_sep):
# col is (column_name, column), use just column data here
dummy = _get_dummies_1d(col[1], prefix=pre, prefix_sep=sep,
dummy_na=dummy_na, sparse=sparse,
drop_first=drop_first, dtype=dtype)
with_dummies.append(dummy)
result = concat(with_dummies, axis=1)
else:
result = _get_dummies_1d(data, prefix, prefix_sep, dummy_na,
sparse=sparse,
drop_first=drop_first,
dtype=dtype)
return result |
Construct 1-0 dummy variables corresponding to designated axis
labels
Parameters
----------
frame : DataFrame
axis : {'major', 'minor'}, default 'minor'
transform : function, default None
Function to apply to axis labels first. For example, to
get "day of week" dummies in a time series regression
you might call::
make_axis_dummies(panel, axis='major',
transform=lambda d: d.weekday())
Returns
-------
dummies : DataFrame
Column names taken from chosen axis | def make_axis_dummies(frame, axis='minor', transform=None):
"""
Construct 1-0 dummy variables corresponding to designated axis
labels
Parameters
----------
frame : DataFrame
axis : {'major', 'minor'}, default 'minor'
transform : function, default None
Function to apply to axis labels first. For example, to
get "day of week" dummies in a time series regression
you might call::
make_axis_dummies(panel, axis='major',
transform=lambda d: d.weekday())
Returns
-------
dummies : DataFrame
Column names taken from chosen axis
"""
numbers = {'major': 0, 'minor': 1}
num = numbers.get(axis, axis)
items = frame.index.levels[num]
codes = frame.index.codes[num]
if transform is not None:
mapped_items = items.map(transform)
codes, items = _factorize_from_iterable(mapped_items.take(codes))
values = np.eye(len(items), dtype=float)
values = values.take(codes, axis=0)
return DataFrame(values, columns=items, index=frame.index) |
Re-orders the values when stacking multiple extension-arrays.
The indirect stacking method used for EAs requires a followup
take to get the order correct.
Parameters
----------
arr : ExtensionArray
n_rows, n_columns : int
The number of rows and columns in the original DataFrame.
Returns
-------
taken : ExtensionArray
The original `arr` with elements re-ordered appropriately
Examples
--------
>>> arr = np.array(['a', 'b', 'c', 'd', 'e', 'f'])
>>> _reorder_for_extension_array_stack(arr, 2, 3)
array(['a', 'c', 'e', 'b', 'd', 'f'], dtype='<U1')
>>> _reorder_for_extension_array_stack(arr, 3, 2)
array(['a', 'd', 'b', 'e', 'c', 'f'], dtype='<U1') | def _reorder_for_extension_array_stack(arr, n_rows, n_columns):
"""
Re-orders the values when stacking multiple extension-arrays.
The indirect stacking method used for EAs requires a followup
take to get the order correct.
Parameters
----------
arr : ExtensionArray
n_rows, n_columns : int
The number of rows and columns in the original DataFrame.
Returns
-------
taken : ExtensionArray
The original `arr` with elements re-ordered appropriately
Examples
--------
>>> arr = np.array(['a', 'b', 'c', 'd', 'e', 'f'])
>>> _reorder_for_extension_array_stack(arr, 2, 3)
array(['a', 'c', 'e', 'b', 'd', 'f'], dtype='<U1')
>>> _reorder_for_extension_array_stack(arr, 3, 2)
array(['a', 'd', 'b', 'e', 'c', 'f'], dtype='<U1')
"""
# final take to get the order correct.
# idx is an indexer like
# [c0r0, c1r0, c2r0, ...,
# c0r1, c1r1, c2r1, ...]
idx = np.arange(n_rows * n_columns).reshape(n_columns, n_rows).T.ravel()
return arr.take(idx) |
Parameters
----------
s: string
Fixed-length string to split
parts: list of (name, length) pairs
Used to break up string, name '_' will be filtered from output.
Returns
-------
Dict of name:contents of string at given location. | def _split_line(s, parts):
"""
Parameters
----------
s: string
Fixed-length string to split
parts: list of (name, length) pairs
Used to break up string, name '_' will be filtered from output.
Returns
-------
Dict of name:contents of string at given location.
"""
out = {}
start = 0
for name, length in parts:
out[name] = s[start:start + length].strip()
start += length
del out['_']
return out |
Parse a vector of float values representing IBM 8 byte floats into
native 8 byte floats. | def _parse_float_vec(vec):
"""
Parse a vector of float values representing IBM 8 byte floats into
native 8 byte floats.
"""
dtype = np.dtype('>u4,>u4')
vec1 = vec.view(dtype=dtype)
xport1 = vec1['f0']
xport2 = vec1['f1']
# Start by setting first half of ieee number to first half of IBM
# number sans exponent
ieee1 = xport1 & 0x00ffffff
# The fraction bit to the left of the binary point in the ieee
# format was set and the number was shifted 0, 1, 2, or 3
# places. This will tell us how to adjust the ibm exponent to be a
# power of 2 ieee exponent and how to shift the fraction bits to
# restore the correct magnitude.
shift = np.zeros(len(vec), dtype=np.uint8)
shift[np.where(xport1 & 0x00200000)] = 1
shift[np.where(xport1 & 0x00400000)] = 2
shift[np.where(xport1 & 0x00800000)] = 3
# shift the ieee number down the correct number of places then
# set the second half of the ieee number to be the second half
# of the ibm number shifted appropriately, ored with the bits
# from the first half that would have been shifted in if we
# could shift a double. All we are worried about are the low
# order 3 bits of the first half since we're only shifting by
# 1, 2, or 3.
ieee1 >>= shift
ieee2 = (xport2 >> shift) | ((xport1 & 0x00000007) << (29 + (3 - shift)))
# clear the 1 bit to the left of the binary point
ieee1 &= 0xffefffff
# set the exponent of the ieee number to be the actual exponent
# plus the shift count + 1023. Or this into the first half of the
# ieee number. The ibm exponent is excess 64 but is adjusted by 65
# since during conversion to ibm format the exponent is
# incremented by 1 and the fraction bits left 4 positions to the
# right of the radix point. (had to add >> 24 because C treats &
# 0x7f as 0x7f000000 and Python doesn't)
ieee1 |= ((((((xport1 >> 24) & 0x7f) - 65) << 2) +
shift + 1023) << 20) | (xport1 & 0x80000000)
ieee = np.empty((len(ieee1),), dtype='>u4,>u4')
ieee['f0'] = ieee1
ieee['f1'] = ieee2
ieee = ieee.view(dtype='>f8')
ieee = ieee.astype('f8')
return ieee |
Get number of records in file.
This is maybe suboptimal because we have to seek to the end of
the file.
Side effect: returns file position to record_start. | def _record_count(self):
"""
Get number of records in file.
This is maybe suboptimal because we have to seek to the end of
the file.
Side effect: returns file position to record_start.
"""
self.filepath_or_buffer.seek(0, 2)
total_records_length = (self.filepath_or_buffer.tell() -
self.record_start)
if total_records_length % 80 != 0:
warnings.warn("xport file may be corrupted")
if self.record_length > 80:
self.filepath_or_buffer.seek(self.record_start)
return total_records_length // self.record_length
self.filepath_or_buffer.seek(-80, 2)
last_card = self.filepath_or_buffer.read(80)
last_card = np.frombuffer(last_card, dtype=np.uint64)
# 8 byte blank
ix = np.flatnonzero(last_card == 2314885530818453536)
if len(ix) == 0:
tail_pad = 0
else:
tail_pad = 8 * len(ix)
self.filepath_or_buffer.seek(self.record_start)
return (total_records_length - tail_pad) // self.record_length |
Reads lines from Xport file and returns as dataframe
Parameters
----------
size : int, defaults to None
Number of lines to read. If None, reads whole file.
Returns
-------
DataFrame | def get_chunk(self, size=None):
"""
Reads lines from Xport file and returns as dataframe
Parameters
----------
size : int, defaults to None
Number of lines to read. If None, reads whole file.
Returns
-------
DataFrame
"""
if size is None:
size = self._chunksize
return self.read(nrows=size) |
raise a helpful message about our construction | def construction_error(tot_items, block_shape, axes, e=None):
""" raise a helpful message about our construction """
passed = tuple(map(int, [tot_items] + list(block_shape)))
# Correcting the user facing error message during dataframe construction
if len(passed) <= 2:
passed = passed[::-1]
implied = tuple(len(ax) for ax in axes)
# Correcting the user facing error message during dataframe construction
if len(implied) <= 2:
implied = implied[::-1]
if passed == implied and e is not None:
raise e
if block_shape[0] == 0:
raise ValueError("Empty data passed with indices specified.")
raise ValueError("Shape of passed values is {0}, indices imply {1}".format(
passed, implied)) |
return a single array of a block that has a single dtype; if dtype is
not None, coerce to this dtype | def _simple_blockify(tuples, dtype):
""" return a single array of a block that has a single dtype; if dtype is
not None, coerce to this dtype
"""
values, placement = _stack_arrays(tuples, dtype)
# CHECK DTYPE?
if dtype is not None and values.dtype != dtype: # pragma: no cover
values = values.astype(dtype)
block = make_block(values, placement=placement)
return [block] |
return an array of blocks that potentially have different dtypes | def _multi_blockify(tuples, dtype=None):
""" return an array of blocks that potentially have different dtypes """
# group by dtype
grouper = itertools.groupby(tuples, lambda x: x[2].dtype)
new_blocks = []
for dtype, tup_block in grouper:
values, placement = _stack_arrays(list(tup_block), dtype)
block = make_block(values, placement=placement)
new_blocks.append(block)
return new_blocks |
return an array of blocks that potentially have different dtypes (and
are sparse) | def _sparse_blockify(tuples, dtype=None):
""" return an array of blocks that potentially have different dtypes (and
are sparse)
"""
new_blocks = []
for i, names, array in tuples:
array = _maybe_to_sparse(array)
block = make_block(array, placement=[i])
new_blocks.append(block)
return new_blocks |
Find the common dtype for `blocks`.
Parameters
----------
blocks : List[Block]
Returns
-------
dtype : Optional[Union[np.dtype, ExtensionDtype]]
None is returned when `blocks` is empty. | def _interleaved_dtype(
blocks: List[Block]
) -> Optional[Union[np.dtype, ExtensionDtype]]:
"""Find the common dtype for `blocks`.
Parameters
----------
blocks : List[Block]
Returns
-------
dtype : Optional[Union[np.dtype, ExtensionDtype]]
None is returned when `blocks` is empty.
"""
if not len(blocks):
return None
return find_common_type([b.dtype for b in blocks]) |
Merge blocks having same dtype, exclude non-consolidating blocks | def _consolidate(blocks):
"""
Merge blocks having same dtype, exclude non-consolidating blocks
"""
# sort by _can_consolidate, dtype
gkey = lambda x: x._consolidate_key
grouper = itertools.groupby(sorted(blocks, key=gkey), gkey)
new_blocks = []
for (_can_consolidate, dtype), group_blocks in grouper:
merged_blocks = _merge_blocks(list(group_blocks), dtype=dtype,
_can_consolidate=_can_consolidate)
new_blocks = _extend_blocks(merged_blocks, new_blocks)
return new_blocks |
Compare two array_like inputs of the same shape or two scalar values
Calls operator.eq or re.search, depending on regex argument. If regex is
True, perform an element-wise regex matching.
Parameters
----------
a : array_like or scalar
b : array_like or scalar
regex : bool, default False
Returns
-------
mask : array_like of bool | def _compare_or_regex_search(a, b, regex=False):
"""
Compare two array_like inputs of the same shape or two scalar values
Calls operator.eq or re.search, depending on regex argument. If regex is
True, perform an element-wise regex matching.
Parameters
----------
a : array_like or scalar
b : array_like or scalar
regex : bool, default False
Returns
-------
mask : array_like of bool
"""
if not regex:
op = lambda x: operator.eq(x, b)
else:
op = np.vectorize(lambda x: bool(re.search(b, x)) if isinstance(x, str)
else False)
is_a_array = isinstance(a, np.ndarray)
is_b_array = isinstance(b, np.ndarray)
# numpy deprecation warning to have i8 vs integer comparisons
if is_datetimelike_v_numeric(a, b):
result = False
# numpy deprecation warning if comparing numeric vs string-like
elif is_numeric_v_string_like(a, b):
result = False
else:
result = op(a)
if is_scalar(result) and (is_a_array or is_b_array):
type_names = [type(a).__name__, type(b).__name__]
if is_a_array:
type_names[0] = 'ndarray(dtype={dtype})'.format(dtype=a.dtype)
if is_b_array:
type_names[1] = 'ndarray(dtype={dtype})'.format(dtype=b.dtype)
raise TypeError(
"Cannot compare types {a!r} and {b!r}".format(a=type_names[0],
b=type_names[1]))
return result |
If two indices overlap, add suffixes to overlapping entries.
If corresponding suffix is empty, the entry is simply converted to string. | def items_overlap_with_suffix(left, lsuffix, right, rsuffix):
"""
If two indices overlap, add suffixes to overlapping entries.
If corresponding suffix is empty, the entry is simply converted to string.
"""
to_rename = left.intersection(right)
if len(to_rename) == 0:
return left, right
else:
if not lsuffix and not rsuffix:
raise ValueError('columns overlap but no suffix specified: '
'{rename}'.format(rename=to_rename))
def renamer(x, suffix):
"""Rename the left and right indices.
If there is overlap, and suffix is not None, add
suffix, otherwise, leave it as-is.
Parameters
----------
x : original column name
suffix : str or None
Returns
-------
x : renamed column name
"""
if x in to_rename and suffix is not None:
return '{x}{suffix}'.format(x=x, suffix=suffix)
return x
lrenamer = partial(renamer, suffix=lsuffix)
rrenamer = partial(renamer, suffix=rsuffix)
return (_transform_index(left, lrenamer),
_transform_index(right, rrenamer)) |
Apply function to all values found in index.
This includes transforming multiindex entries separately.
Only apply function to one level of the MultiIndex if level is specified. | def _transform_index(index, func, level=None):
"""
Apply function to all values found in index.
This includes transforming multiindex entries separately.
Only apply function to one level of the MultiIndex if level is specified.
"""
if isinstance(index, MultiIndex):
if level is not None:
items = [tuple(func(y) if i == level else y
for i, y in enumerate(x)) for x in index]
else:
items = [tuple(func(y) for y in x) for x in index]
return MultiIndex.from_tuples(items, names=index.names)
else:
items = [func(x) for x in index]
return Index(items, name=index.name, tupleize_cols=False) |
Faster version of set(arr) for sequences of small numbers. | def _fast_count_smallints(arr):
"""Faster version of set(arr) for sequences of small numbers."""
counts = np.bincount(arr.astype(np.int_))
nz = counts.nonzero()[0]
return np.c_[nz, counts[nz]] |
Concatenate block managers into one.
Parameters
----------
mgrs_indexers : list of (BlockManager, {axis: indexer,...}) tuples
axes : list of Index
concat_axis : int
copy : bool | def concatenate_block_managers(mgrs_indexers, axes, concat_axis, copy):
"""
Concatenate block managers into one.
Parameters
----------
mgrs_indexers : list of (BlockManager, {axis: indexer,...}) tuples
axes : list of Index
concat_axis : int
copy : bool
"""
concat_plans = [get_mgr_concatenation_plan(mgr, indexers)
for mgr, indexers in mgrs_indexers]
concat_plan = combine_concat_plans(concat_plans, concat_axis)
blocks = []
for placement, join_units in concat_plan:
if len(join_units) == 1 and not join_units[0].indexers:
b = join_units[0].block
values = b.values
if copy:
values = values.copy()
elif not copy:
values = values.view()
b = b.make_block_same_class(values, placement=placement)
elif is_uniform_join_units(join_units):
b = join_units[0].block.concat_same_type(
[ju.block for ju in join_units], placement=placement)
else:
b = make_block(
concatenate_join_units(join_units, concat_axis, copy=copy),
placement=placement)
blocks.append(b)
return BlockManager(blocks, axes) |
return an empty BlockManager with the items axis of len 0 | def make_empty(self, axes=None):
""" return an empty BlockManager with the items axis of len 0 """
if axes is None:
axes = [ensure_index([])] + [ensure_index(a)
for a in self.axes[1:]]
# preserve dtype if possible
if self.ndim == 1:
blocks = np.array([], dtype=self.array_dtype)
else:
blocks = []
return self.__class__(blocks, axes) |
Rename one of axes.
Parameters
----------
mapper : unary callable
axis : int
copy : boolean, default True
level : int, default None | def rename_axis(self, mapper, axis, copy=True, level=None):
"""
Rename one of axes.
Parameters
----------
mapper : unary callable
axis : int
copy : boolean, default True
level : int, default None
"""
obj = self.copy(deep=copy)
obj.set_axis(axis, _transform_index(self.axes[axis], mapper, level))
return obj |
Update mgr._blknos / mgr._blklocs. | def _rebuild_blknos_and_blklocs(self):
"""
Update mgr._blknos / mgr._blklocs.
"""
new_blknos = np.empty(self.shape[0], dtype=np.int64)
new_blklocs = np.empty(self.shape[0], dtype=np.int64)
new_blknos.fill(-1)
new_blklocs.fill(-1)
for blkno, blk in enumerate(self.blocks):
rl = blk.mgr_locs
new_blknos[rl.indexer] = blkno
new_blklocs[rl.indexer] = np.arange(len(rl))
if (new_blknos == -1).any():
raise AssertionError("Gaps in blk ref_locs")
self._blknos = new_blknos
self._blklocs = new_blklocs |
return a dict of the counts of the function in BlockManager | def _get_counts(self, f):
""" return a dict of the counts of the function in BlockManager """
self._consolidate_inplace()
counts = dict()
for b in self.blocks:
v = f(b)
counts[v] = counts.get(v, 0) + b.shape[0]
return counts |
iterate over the blocks, collect and create a new block manager
Parameters
----------
f : the callable or function name to operate on at the block level
axes : optional (if not supplied, use self.axes)
filter : list, if supplied, only call the block if the filter is in
the block
do_integrity_check : boolean, default False. Do the block manager
integrity check
consolidate: boolean, default True. Join together blocks having same
dtype
Returns
-------
Block Manager (new object) | def apply(self, f, axes=None, filter=None, do_integrity_check=False,
consolidate=True, **kwargs):
"""
iterate over the blocks, collect and create a new block manager
Parameters
----------
f : the callable or function name to operate on at the block level
axes : optional (if not supplied, use self.axes)
filter : list, if supplied, only call the block if the filter is in
the block
do_integrity_check : boolean, default False. Do the block manager
integrity check
consolidate: boolean, default True. Join together blocks having same
dtype
Returns
-------
Block Manager (new object)
"""
result_blocks = []
# filter kwarg is used in replace-* family of methods
if filter is not None:
filter_locs = set(self.items.get_indexer_for(filter))
if len(filter_locs) == len(self.items):
# All items are included, as if there were no filtering
filter = None
else:
kwargs['filter'] = filter_locs
if consolidate:
self._consolidate_inplace()
if f == 'where':
align_copy = True
if kwargs.get('align', True):
align_keys = ['other', 'cond']
else:
align_keys = ['cond']
elif f == 'putmask':
align_copy = False
if kwargs.get('align', True):
align_keys = ['new', 'mask']
else:
align_keys = ['mask']
elif f == 'fillna':
# fillna internally does putmask, maybe it's better to do this
# at mgr, not block level?
align_copy = False
align_keys = ['value']
else:
align_keys = []
# TODO(EA): may interfere with ExtensionBlock.setitem for blocks
# with a .values attribute.
aligned_args = {k: kwargs[k]
for k in align_keys
if hasattr(kwargs[k], 'values') and
not isinstance(kwargs[k], ABCExtensionArray)}
for b in self.blocks:
if filter is not None:
if not b.mgr_locs.isin(filter_locs).any():
result_blocks.append(b)
continue
if aligned_args:
b_items = self.items[b.mgr_locs.indexer]
for k, obj in aligned_args.items():
axis = getattr(obj, '_info_axis_number', 0)
kwargs[k] = obj.reindex(b_items, axis=axis,
copy=align_copy)
applied = getattr(b, f)(**kwargs)
result_blocks = _extend_blocks(applied, result_blocks)
if len(result_blocks) == 0:
return self.make_empty(axes or self.axes)
bm = self.__class__(result_blocks, axes or self.axes,
do_integrity_check=do_integrity_check)
bm._consolidate_inplace()
return bm |
Iterate over blocks applying quantile reduction.
This routine is intended for reduction type operations and
will do inference on the generated blocks.
Parameters
----------
axis: reduction axis, default 0
consolidate: boolean, default True. Join together blocks having same
dtype
transposed: boolean, default False
we are holding transposed data
interpolation : type of interpolation, default 'linear'
qs : a scalar or list of the quantiles to be computed
numeric_only : ignored
Returns
-------
Block Manager (new object) | def quantile(self, axis=0, consolidate=True, transposed=False,
interpolation='linear', qs=None, numeric_only=None):
"""
Iterate over blocks applying quantile reduction.
This routine is intended for reduction type operations and
will do inference on the generated blocks.
Parameters
----------
axis: reduction axis, default 0
consolidate: boolean, default True. Join together blocks having same
dtype
transposed: boolean, default False
we are holding transposed data
interpolation : type of interpolation, default 'linear'
qs : a scalar or list of the quantiles to be computed
numeric_only : ignored
Returns
-------
Block Manager (new object)
"""
# Series dispatches to DataFrame for quantile, which allows us to
# simplify some of the code here and in the blocks
assert self.ndim >= 2
if consolidate:
self._consolidate_inplace()
def get_axe(block, qs, axes):
from pandas import Float64Index
if is_list_like(qs):
ax = Float64Index(qs)
elif block.ndim == 1:
ax = Float64Index([qs])
else:
ax = axes[0]
return ax
axes, blocks = [], []
for b in self.blocks:
block = b.quantile(axis=axis, qs=qs, interpolation=interpolation)
axe = get_axe(b, qs, axes=self.axes)
axes.append(axe)
blocks.append(block)
# note that some DatetimeTZ, Categorical are always ndim==1
ndim = {b.ndim for b in blocks}
assert 0 not in ndim, ndim
if 2 in ndim:
new_axes = list(self.axes)
# multiple blocks that are reduced
if len(blocks) > 1:
new_axes[1] = axes[0]
# reset the placement to the original
for b, sb in zip(blocks, self.blocks):
b.mgr_locs = sb.mgr_locs
else:
new_axes[axis] = Index(np.concatenate(
[ax.values for ax in axes]))
if transposed:
new_axes = new_axes[::-1]
blocks = [b.make_block(b.values.T,
placement=np.arange(b.shape[1])
) for b in blocks]
return self.__class__(blocks, new_axes)
# single block, i.e. ndim == {1}
values = _concat._concat_compat([b.values for b in blocks])
# compute the orderings of our original data
if len(self.blocks) > 1:
indexer = np.empty(len(self.axes[0]), dtype=np.intp)
i = 0
for b in self.blocks:
for j in b.mgr_locs:
indexer[j] = i
i = i + 1
values = values.take(indexer)
return SingleBlockManager(
[make_block(values,
ndim=1,
placement=np.arange(len(values)))],
axes[0]) |
do a list replace | def replace_list(self, src_list, dest_list, inplace=False, regex=False):
""" do a list replace """
inplace = validate_bool_kwarg(inplace, 'inplace')
# figure out our mask a-priori to avoid repeated replacements
values = self.as_array()
def comp(s, regex=False):
"""
Generate a bool array by perform an equality check, or perform
an element-wise regular expression matching
"""
if isna(s):
return isna(values)
if hasattr(s, 'asm8'):
return _compare_or_regex_search(maybe_convert_objects(values),
getattr(s, 'asm8'), regex)
return _compare_or_regex_search(values, s, regex)
masks = [comp(s, regex) for i, s in enumerate(src_list)]
result_blocks = []
src_len = len(src_list) - 1
for blk in self.blocks:
# its possible to get multiple result blocks here
# replace ALWAYS will return a list
rb = [blk if inplace else blk.copy()]
for i, (s, d) in enumerate(zip(src_list, dest_list)):
new_rb = []
for b in rb:
m = masks[i][b.mgr_locs.indexer]
convert = i == src_len
result = b._replace_coerce(mask=m, to_replace=s, value=d,
inplace=inplace,
convert=convert, regex=regex)
if m.any():
new_rb = _extend_blocks(result, new_rb)
else:
new_rb.append(b)
rb = new_rb
result_blocks.extend(rb)
bm = self.__class__(result_blocks, self.axes)
bm._consolidate_inplace()
return bm |
Parameters
----------
copy : boolean, default False
Whether to copy the blocks | def get_bool_data(self, copy=False):
"""
Parameters
----------
copy : boolean, default False
Whether to copy the blocks
"""
self._consolidate_inplace()
return self.combine([b for b in self.blocks if b.is_bool], copy) |
Parameters
----------
copy : boolean, default False
Whether to copy the blocks | def get_numeric_data(self, copy=False):
"""
Parameters
----------
copy : boolean, default False
Whether to copy the blocks
"""
self._consolidate_inplace()
return self.combine([b for b in self.blocks if b.is_numeric], copy) |
return a new manager with the blocks | def combine(self, blocks, copy=True):
""" return a new manager with the blocks """
if len(blocks) == 0:
return self.make_empty()
# FIXME: optimization potential
indexer = np.sort(np.concatenate([b.mgr_locs.as_array
for b in blocks]))
inv_indexer = lib.get_reverse_indexer(indexer, self.shape[0])
new_blocks = []
for b in blocks:
b = b.copy(deep=copy)
b.mgr_locs = algos.take_1d(inv_indexer, b.mgr_locs.as_array,
axis=0, allow_fill=False)
new_blocks.append(b)
axes = list(self.axes)
axes[0] = self.items.take(indexer)
return self.__class__(new_blocks, axes, do_integrity_check=False) |
Make deep or shallow copy of BlockManager
Parameters
----------
deep : boolean o rstring, default True
If False, return shallow copy (do not copy data)
If 'all', copy data and a deep copy of the index
Returns
-------
copy : BlockManager | def copy(self, deep=True):
"""
Make deep or shallow copy of BlockManager
Parameters
----------
deep : boolean o rstring, default True
If False, return shallow copy (do not copy data)
If 'all', copy data and a deep copy of the index
Returns
-------
copy : BlockManager
"""
# this preserves the notion of view copying of axes
if deep:
if deep == 'all':
copy = lambda ax: ax.copy(deep=True)
else:
copy = lambda ax: ax.view()
new_axes = [copy(ax) for ax in self.axes]
else:
new_axes = list(self.axes)
return self.apply('copy', axes=new_axes, deep=deep,
do_integrity_check=False) |
Convert the blockmanager data into an numpy array.
Parameters
----------
transpose : boolean, default False
If True, transpose the return array
items : list of strings or None
Names of block items that will be included in the returned
array. ``None`` means that all block items will be used
Returns
-------
arr : ndarray | def as_array(self, transpose=False, items=None):
"""Convert the blockmanager data into an numpy array.
Parameters
----------
transpose : boolean, default False
If True, transpose the return array
items : list of strings or None
Names of block items that will be included in the returned
array. ``None`` means that all block items will be used
Returns
-------
arr : ndarray
"""
if len(self.blocks) == 0:
arr = np.empty(self.shape, dtype=float)
return arr.transpose() if transpose else arr
if items is not None:
mgr = self.reindex_axis(items, axis=0)
else:
mgr = self
if self._is_single_block and mgr.blocks[0].is_datetimetz:
# TODO(Block.get_values): Make DatetimeTZBlock.get_values
# always be object dtype. Some callers seem to want the
# DatetimeArray (previously DTI)
arr = mgr.blocks[0].get_values(dtype=object)
elif self._is_single_block or not self.is_mixed_type:
arr = np.asarray(mgr.blocks[0].get_values())
else:
arr = mgr._interleave()
return arr.transpose() if transpose else arr |
Return ndarray from blocks with specified item order
Items must be contained in the blocks | def _interleave(self):
"""
Return ndarray from blocks with specified item order
Items must be contained in the blocks
"""
from pandas.core.dtypes.common import is_sparse
dtype = _interleaved_dtype(self.blocks)
# TODO: https://github.com/pandas-dev/pandas/issues/22791
# Give EAs some input on what happens here. Sparse needs this.
if is_sparse(dtype):
dtype = dtype.subtype
elif is_extension_array_dtype(dtype):
dtype = 'object'
result = np.empty(self.shape, dtype=dtype)
itemmask = np.zeros(self.shape[0])
for blk in self.blocks:
rl = blk.mgr_locs
result[rl.indexer] = blk.get_values(dtype)
itemmask[rl.indexer] = 1
if not itemmask.all():
raise AssertionError('Some items were not contained in blocks')
return result |
Return a dict of str(dtype) -> BlockManager
Parameters
----------
copy : boolean, default True
Returns
-------
values : a dict of dtype -> BlockManager
Notes
-----
This consolidates based on str(dtype) | def to_dict(self, copy=True):
"""
Return a dict of str(dtype) -> BlockManager
Parameters
----------
copy : boolean, default True
Returns
-------
values : a dict of dtype -> BlockManager
Notes
-----
This consolidates based on str(dtype)
"""
self._consolidate_inplace()
bd = {}
for b in self.blocks:
bd.setdefault(str(b.dtype), []).append(b)
return {dtype: self.combine(blocks, copy=copy)
for dtype, blocks in bd.items()} |
get a cross sectional for a given location in the
items ; handle dups
return the result, is *could* be a view in the case of a
single block | def fast_xs(self, loc):
"""
get a cross sectional for a given location in the
items ; handle dups
return the result, is *could* be a view in the case of a
single block
"""
if len(self.blocks) == 1:
return self.blocks[0].iget((slice(None), loc))
items = self.items
# non-unique (GH4726)
if not items.is_unique:
result = self._interleave()
if self.ndim == 2:
result = result.T
return result[loc]
# unique
dtype = _interleaved_dtype(self.blocks)
n = len(items)
if is_extension_array_dtype(dtype):
# we'll eventually construct an ExtensionArray.
result = np.empty(n, dtype=object)
else:
result = np.empty(n, dtype=dtype)
for blk in self.blocks:
# Such assignment may incorrectly coerce NaT to None
# result[blk.mgr_locs] = blk._slice((slice(None), loc))
for i, rl in enumerate(blk.mgr_locs):
result[rl] = blk._try_coerce_result(blk.iget((i, loc)))
if is_extension_array_dtype(dtype):
result = dtype.construct_array_type()._from_sequence(
result, dtype=dtype
)
return result |
Join together blocks having same dtype
Returns
-------
y : BlockManager | def consolidate(self):
"""
Join together blocks having same dtype
Returns
-------
y : BlockManager
"""
if self.is_consolidated():
return self
bm = self.__class__(self.blocks, self.axes)
bm._is_consolidated = False
bm._consolidate_inplace()
return bm |
Return values for selected item (ndarray or BlockManager). | def get(self, item, fastpath=True):
"""
Return values for selected item (ndarray or BlockManager).
"""
if self.items.is_unique:
if not isna(item):
loc = self.items.get_loc(item)
else:
indexer = np.arange(len(self.items))[isna(self.items)]
# allow a single nan location indexer
if not is_scalar(indexer):
if len(indexer) == 1:
loc = indexer.item()
else:
raise ValueError("cannot label index with a null key")
return self.iget(loc, fastpath=fastpath)
else:
if isna(item):
raise TypeError("cannot label index with a null key")
indexer = self.items.get_indexer_for([item])
return self.reindex_indexer(new_axis=self.items[indexer],
indexer=indexer, axis=0,
allow_dups=True) |
Return the data as a SingleBlockManager if fastpath=True and possible
Otherwise return as a ndarray | def iget(self, i, fastpath=True):
"""
Return the data as a SingleBlockManager if fastpath=True and possible
Otherwise return as a ndarray
"""
block = self.blocks[self._blknos[i]]
values = block.iget(self._blklocs[i])
if not fastpath or not block._box_to_block_values or values.ndim != 1:
return values
# fastpath shortcut for select a single-dim from a 2-dim BM
return SingleBlockManager(
[block.make_block_same_class(values,
placement=slice(0, len(values)),
ndim=1)],
self.axes[1]) |
Delete selected item (items if non-unique) in-place. | def delete(self, item):
"""
Delete selected item (items if non-unique) in-place.
"""
indexer = self.items.get_loc(item)
is_deleted = np.zeros(self.shape[0], dtype=np.bool_)
is_deleted[indexer] = True
ref_loc_offset = -is_deleted.cumsum()
is_blk_deleted = [False] * len(self.blocks)
if isinstance(indexer, int):
affected_start = indexer
else:
affected_start = is_deleted.nonzero()[0][0]
for blkno, _ in _fast_count_smallints(self._blknos[affected_start:]):
blk = self.blocks[blkno]
bml = blk.mgr_locs
blk_del = is_deleted[bml.indexer].nonzero()[0]
if len(blk_del) == len(bml):
is_blk_deleted[blkno] = True
continue
elif len(blk_del) != 0:
blk.delete(blk_del)
bml = blk.mgr_locs
blk.mgr_locs = bml.add(ref_loc_offset[bml.indexer])
# FIXME: use Index.delete as soon as it uses fastpath=True
self.axes[0] = self.items[~is_deleted]
self.blocks = tuple(b for blkno, b in enumerate(self.blocks)
if not is_blk_deleted[blkno])
self._shape = None
self._rebuild_blknos_and_blklocs() |
Set new item in-place. Does not consolidate. Adds new Block if not
contained in the current set of items | def set(self, item, value):
"""
Set new item in-place. Does not consolidate. Adds new Block if not
contained in the current set of items
"""
# FIXME: refactor, clearly separate broadcasting & zip-like assignment
# can prob also fix the various if tests for sparse/categorical
# TODO(EA): Remove an is_extension_ when all extension types satisfy
# the interface
value_is_extension_type = (is_extension_type(value) or
is_extension_array_dtype(value))
# categorical/spares/datetimetz
if value_is_extension_type:
def value_getitem(placement):
return value
else:
if value.ndim == self.ndim - 1:
value = _safe_reshape(value, (1,) + value.shape)
def value_getitem(placement):
return value
else:
def value_getitem(placement):
return value[placement.indexer]
if value.shape[1:] != self.shape[1:]:
raise AssertionError('Shape of new values must be compatible '
'with manager shape')
try:
loc = self.items.get_loc(item)
except KeyError:
# This item wasn't present, just insert at end
self.insert(len(self.items), item, value)
return
if isinstance(loc, int):
loc = [loc]
blknos = self._blknos[loc]
blklocs = self._blklocs[loc].copy()
unfit_mgr_locs = []
unfit_val_locs = []
removed_blknos = []
for blkno, val_locs in libinternals.get_blkno_placements(blknos,
self.nblocks,
group=True):
blk = self.blocks[blkno]
blk_locs = blklocs[val_locs.indexer]
if blk.should_store(value):
blk.set(blk_locs, value_getitem(val_locs))
else:
unfit_mgr_locs.append(blk.mgr_locs.as_array[blk_locs])
unfit_val_locs.append(val_locs)
# If all block items are unfit, schedule the block for removal.
if len(val_locs) == len(blk.mgr_locs):
removed_blknos.append(blkno)
else:
self._blklocs[blk.mgr_locs.indexer] = -1
blk.delete(blk_locs)
self._blklocs[blk.mgr_locs.indexer] = np.arange(len(blk))
if len(removed_blknos):
# Remove blocks & update blknos accordingly
is_deleted = np.zeros(self.nblocks, dtype=np.bool_)
is_deleted[removed_blknos] = True
new_blknos = np.empty(self.nblocks, dtype=np.int64)
new_blknos.fill(-1)
new_blknos[~is_deleted] = np.arange(self.nblocks -
len(removed_blknos))
self._blknos = algos.take_1d(new_blknos, self._blknos, axis=0,
allow_fill=False)
self.blocks = tuple(blk for i, blk in enumerate(self.blocks)
if i not in set(removed_blknos))
if unfit_val_locs:
unfit_mgr_locs = np.concatenate(unfit_mgr_locs)
unfit_count = len(unfit_mgr_locs)
new_blocks = []
if value_is_extension_type:
# This code (ab-)uses the fact that sparse blocks contain only
# one item.
new_blocks.extend(
make_block(values=value.copy(), ndim=self.ndim,
placement=slice(mgr_loc, mgr_loc + 1))
for mgr_loc in unfit_mgr_locs)
self._blknos[unfit_mgr_locs] = (np.arange(unfit_count) +
len(self.blocks))
self._blklocs[unfit_mgr_locs] = 0
else:
# unfit_val_locs contains BlockPlacement objects
unfit_val_items = unfit_val_locs[0].append(unfit_val_locs[1:])
new_blocks.append(
make_block(values=value_getitem(unfit_val_items),
ndim=self.ndim, placement=unfit_mgr_locs))
self._blknos[unfit_mgr_locs] = len(self.blocks)
self._blklocs[unfit_mgr_locs] = np.arange(unfit_count)
self.blocks += tuple(new_blocks)
# Newly created block's dtype may already be present.
self._known_consolidated = False |