codekingpro/portable-devtools

1from __future__ import annotations2 3import contextlib4import os5import sys6from typing import TYPE_CHECKING, TypeVar, Union7 8from more_itertools import unique_everseen9 10if TYPE_CHECKING:11    from typing_extensions import TypeAlias12 13StrPath: TypeAlias = Union[str, os.PathLike[str]]  #  Same as _typeshed.StrPath14StrPathT = TypeVar("StrPathT", bound=Union[str, os.PathLike[str]])15 16 17def ensure_directory(path):18    """Ensure that the parent directory of `path` exists"""19    dirname = os.path.dirname(path)20    os.makedirs(dirname, exist_ok=True)21 22 23def same_path(p1: StrPath, p2: StrPath) -> bool:24    """Differs from os.path.samefile because it does not require paths to exist.25    Purely string based (no comparison between i-nodes).26    >>> same_path("a/b", "./a/b")27    True28    >>> same_path("a/b", "a/./b")29    True30    >>> same_path("a/b", "././a/b")31    True32    >>> same_path("a/b", "./a/b/c/..")33    True34    >>> same_path("a/b", "../a/b/c")35    False36    >>> same_path("a", "a/b")37    False38    """39    return normpath(p1) == normpath(p2)40 41 42def _cygwin_patch(filename: StrPath):  # pragma: nocover43    """44    Contrary to POSIX 2008, on Cygwin, getcwd (3) contains45    symlink components. Using46    os.path.abspath() works around this limitation. A fix in os.getcwd()47    would probably better, in Cygwin even more so, except48    that this seems to be by design...49    """50    return os.path.abspath(filename) if sys.platform == 'cygwin' else filename51 52 53def normpath(filename: StrPath) -> str:54    """Normalize a file/dir name for comparison purposes."""55    return os.path.normcase(os.path.realpath(os.path.normpath(_cygwin_patch(filename))))56 57 58@contextlib.contextmanager59def paths_on_pythonpath(paths):60    """61    Add the indicated paths to the head of the PYTHONPATH environment62    variable so that subprocesses will also see the packages at63    these paths.64 65    Do this in a context that restores the value on exit.66 67    >>> getfixture('monkeypatch').setenv('PYTHONPATH', 'anything')68    >>> with paths_on_pythonpath(['foo', 'bar']):69    ...     assert 'foo' in os.environ['PYTHONPATH']70    ...     assert 'anything' in os.environ['PYTHONPATH']71    >>> os.environ['PYTHONPATH']72    'anything'73 74    >>> getfixture('monkeypatch').delenv('PYTHONPATH')75    >>> with paths_on_pythonpath(['foo', 'bar']):76    ...     assert 'foo' in os.environ['PYTHONPATH']77    >>> os.environ.get('PYTHONPATH')78    """79    nothing = object()80    orig_pythonpath = os.environ.get('PYTHONPATH', nothing)81    current_pythonpath = os.environ.get('PYTHONPATH', '')82    try:83        prefix = os.pathsep.join(unique_everseen(paths))84        to_join = filter(None, [prefix, current_pythonpath])85        new_path = os.pathsep.join(to_join)86        if new_path:87            os.environ['PYTHONPATH'] = new_path88        yield89    finally:90        if orig_pythonpath is nothing:91            os.environ.pop('PYTHONPATH', None)92        else:93            os.environ['PYTHONPATH'] = orig_pythonpath94