forked from 170010011/fr
59 lines
2.4 KiB
Python
59 lines
2.4 KiB
Python
"""
|
|
Backport of PEP 562.
|
|
|
|
https://pypi.org/search/?q=pep562
|
|
|
|
Licensed under MIT
|
|
Copyright (c) 2018 Isaac Muse <isaacmuse@gmail.com>
|
|
|
|
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
|
|
documentation files (the "Software"), to deal in the Software without restriction, including without limitation
|
|
the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
|
|
and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
|
|
|
|
The above copyright notice and this permission notice shall be included in all copies or substantial portions
|
|
of the Software.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
|
|
TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
|
THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
|
|
CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
|
|
IN THE SOFTWARE.
|
|
"""
|
|
from __future__ import unicode_literals
|
|
import sys
|
|
|
|
__all__ = ('Pep562',)
|
|
|
|
|
|
class Pep562(object):
|
|
"""
|
|
Backport of PEP 562 <https://pypi.org/search/?q=pep562>.
|
|
|
|
Wraps the module in a class that exposes the mechanics to override `__dir__` and `__getattr__`.
|
|
The given module will be searched for overrides of `__dir__` and `__getattr__` and use them when needed.
|
|
"""
|
|
|
|
def __init__(self, name):
|
|
"""Acquire `__getattr__` and `__dir__`, but only replace module for versions less than Python 3.7."""
|
|
|
|
self._module = sys.modules[name]
|
|
self._get_attr = getattr(self._module, '__getattr__', None)
|
|
self._get_dir = getattr(self._module, '__dir__', None)
|
|
sys.modules[name] = self
|
|
|
|
def __dir__(self):
|
|
"""Return the overridden `dir` if one was provided, else apply `dir` to the module."""
|
|
|
|
return self._get_dir() if self._get_dir else dir(self._module)
|
|
|
|
def __getattr__(self, name):
|
|
"""Attempt to retrieve the attribute from the module, and if missing, use the overridden function if present."""
|
|
|
|
try:
|
|
return getattr(self._module, name)
|
|
except AttributeError:
|
|
if self._get_attr:
|
|
return self._get_attr(name)
|
|
raise
|