| from __future__ import annotations |
|
|
| import contextlib |
| import os |
| import sys |
| from typing import TYPE_CHECKING, TypeVar, Union |
|
|
| from more_itertools import unique_everseen |
|
|
| if TYPE_CHECKING: |
| from typing_extensions import TypeAlias |
|
|
| StrPath: TypeAlias = Union[str, os.PathLike[str]] |
| StrPathT = TypeVar("StrPathT", bound=Union[str, os.PathLike[str]]) |
|
|
|
|
| def ensure_directory(path): |
| """Ensure that the parent directory of `path` exists""" |
| dirname = os.path.dirname(path) |
| os.makedirs(dirname, exist_ok=True) |
|
|
|
|
| def same_path(p1: StrPath, p2: StrPath) -> bool: |
| """Differs from os.path.samefile because it does not require paths to exist. |
| Purely string based (no comparison between i-nodes). |
| >>> same_path("a/b", "./a/b") |
| True |
| >>> same_path("a/b", "a/./b") |
| True |
| >>> same_path("a/b", "././a/b") |
| True |
| >>> same_path("a/b", "./a/b/c/..") |
| True |
| >>> same_path("a/b", "../a/b/c") |
| False |
| >>> same_path("a", "a/b") |
| False |
| """ |
| return normpath(p1) == normpath(p2) |
|
|
|
|
| def _cygwin_patch(filename: StrPath): |
| """ |
| Contrary to POSIX 2008, on Cygwin, getcwd (3) contains |
| symlink components. Using |
| os.path.abspath() works around this limitation. A fix in os.getcwd() |
| would probably better, in Cygwin even more so, except |
| that this seems to be by design... |
| """ |
| return os.path.abspath(filename) if sys.platform == 'cygwin' else filename |
|
|
|
|
| def normpath(filename: StrPath) -> str: |
| """Normalize a file/dir name for comparison purposes.""" |
| return os.path.normcase(os.path.realpath(os.path.normpath(_cygwin_patch(filename)))) |
|
|
|
|
| @contextlib.contextmanager |
| def paths_on_pythonpath(paths): |
| """ |
| Add the indicated paths to the head of the PYTHONPATH environment |
| variable so that subprocesses will also see the packages at |
| these paths. |
| |
| Do this in a context that restores the value on exit. |
| |
| >>> getfixture('monkeypatch').setenv('PYTHONPATH', 'anything') |
| >>> with paths_on_pythonpath(['foo', 'bar']): |
| ... assert 'foo' in os.environ['PYTHONPATH'] |
| ... assert 'anything' in os.environ['PYTHONPATH'] |
| >>> os.environ['PYTHONPATH'] |
| 'anything' |
| |
| >>> getfixture('monkeypatch').delenv('PYTHONPATH') |
| >>> with paths_on_pythonpath(['foo', 'bar']): |
| ... assert 'foo' in os.environ['PYTHONPATH'] |
| >>> os.environ.get('PYTHONPATH') |
| """ |
| nothing = object() |
| orig_pythonpath = os.environ.get('PYTHONPATH', nothing) |
| current_pythonpath = os.environ.get('PYTHONPATH', '') |
| try: |
| prefix = os.pathsep.join(unique_everseen(paths)) |
| to_join = filter(None, [prefix, current_pythonpath]) |
| new_path = os.pathsep.join(to_join) |
| if new_path: |
| os.environ['PYTHONPATH'] = new_path |
| yield |
| finally: |
| if orig_pythonpath is nothing: |
| os.environ.pop('PYTHONPATH', None) |
| else: |
| os.environ['PYTHONPATH'] = orig_pythonpath |
|
|
