# -*- coding: utf-8 -*- # The MIT License (MIT) # # Copyright (c) 2018 Laurent LAPORTE # # 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. import contextlib import os # modified_environ codes come from https://github.com/laurent-laporte-pro/stackoverflow-q2059482/blob/master/demo/environ_ctx.py @contextlib.contextmanager def modified_environ(*remove, **update): """ Temporarily updates the ``os.environ`` dictionary in-place. The ``os.environ`` dictionary is updated in-place so that the modification is sure to work in all situations. :param remove: Environment variables to remove. :param update: Dictionary of environment variables and values to add/update. """ env = os.environ update = update or {} remove = remove or [] # List of environment variables being updated or removed. stomped = (set(update.keys()) | set(remove)) & set(env.keys()) # Environment variables and values to restore on exit. update_after = {k: env[k] for k in stomped} # Environment variables and values to remove on exit. remove_after = frozenset(k for k in update if k not in env) try: env.update(update) [env.pop(k, None) for k in remove] yield finally: env.update(update_after) [env.pop(k) for k in remove_after]