|
|
""" A universal module with functions / classes without dependencies. """ |
|
|
import functools |
|
|
import re |
|
|
import os |
|
|
|
|
|
|
|
|
_sep = os.path.sep |
|
|
if os.path.altsep is not None: |
|
|
_sep += os.path.altsep |
|
|
_path_re = re.compile(r'(?:\.[^{0}]+|[{0}]__init__\.py)$'.format(re.escape(_sep))) |
|
|
del _sep |
|
|
|
|
|
|
|
|
def to_list(func): |
|
|
def wrapper(*args, **kwargs): |
|
|
return list(func(*args, **kwargs)) |
|
|
return wrapper |
|
|
|
|
|
|
|
|
def to_tuple(func): |
|
|
def wrapper(*args, **kwargs): |
|
|
return tuple(func(*args, **kwargs)) |
|
|
return wrapper |
|
|
|
|
|
|
|
|
def unite(iterable): |
|
|
"""Turns a two dimensional array into a one dimensional.""" |
|
|
return set(typ for types in iterable for typ in types) |
|
|
|
|
|
|
|
|
class UncaughtAttributeError(Exception): |
|
|
""" |
|
|
Important, because `__getattr__` and `hasattr` catch AttributeErrors |
|
|
implicitly. This is really evil (mainly because of `__getattr__`). |
|
|
Therefore this class originally had to be derived from `BaseException` |
|
|
instead of `Exception`. But because I removed relevant `hasattr` from |
|
|
the code base, we can now switch back to `Exception`. |
|
|
|
|
|
:param base: return values of sys.exc_info(). |
|
|
""" |
|
|
|
|
|
|
|
|
def safe_property(func): |
|
|
return property(reraise_uncaught(func)) |
|
|
|
|
|
|
|
|
def reraise_uncaught(func): |
|
|
""" |
|
|
Re-throw uncaught `AttributeError`. |
|
|
|
|
|
Usage: Put ``@rethrow_uncaught`` in front of the function |
|
|
which does **not** suppose to raise `AttributeError`. |
|
|
|
|
|
AttributeError is easily get caught by `hasattr` and another |
|
|
``except AttributeError`` clause. This becomes problem when you use |
|
|
a lot of "dynamic" attributes (e.g., using ``@property``) because you |
|
|
can't distinguish if the property does not exist for real or some code |
|
|
inside of the "dynamic" attribute through that error. In a well |
|
|
written code, such error should not exist but getting there is very |
|
|
difficult. This decorator is to help us getting there by changing |
|
|
`AttributeError` to `UncaughtAttributeError` to avoid unexpected catch. |
|
|
This helps us noticing bugs earlier and facilitates debugging. |
|
|
""" |
|
|
@functools.wraps(func) |
|
|
def wrapper(*args, **kwds): |
|
|
try: |
|
|
return func(*args, **kwds) |
|
|
except AttributeError as e: |
|
|
raise UncaughtAttributeError(e) from e |
|
|
return wrapper |
|
|
|
|
|
|
|
|
class PushBackIterator: |
|
|
def __init__(self, iterator): |
|
|
self.pushes = [] |
|
|
self.iterator = iterator |
|
|
self.current = None |
|
|
|
|
|
def push_back(self, value): |
|
|
self.pushes.append(value) |
|
|
|
|
|
def __iter__(self): |
|
|
return self |
|
|
|
|
|
def __next__(self): |
|
|
if self.pushes: |
|
|
self.current = self.pushes.pop() |
|
|
else: |
|
|
self.current = next(self.iterator) |
|
|
return self.current |
|
|
|
