Lib/pathlib/_abc.py

cpython 3.14 @ ab2d84fe1023/Lib/pathlib/_abc.py ↗

Lib/pathlib/_abc.py defines the abstract path base classes introduced in CPython 3.12. PurePath provides all string-manipulation operations that do not touch the filesystem. Path extends it with I/O operations. The concrete PosixPath and WindowsPath subclasses live in Lib/pathlib/_local.py.

Map

Lines	Symbol	Role
1-80	_PathParents	Sequence of parent paths
81-350	PurePath	String manipulation: parse, join, parent, name, suffix
351-500	PurePath.relative_to, is_relative_to, match	Comparison operations
501-620	PathBase	Abstract I/O protocol (open, stat, iterdir, etc.)

Reading

PurePath parsing

PurePath.__new__ joins all arguments with os.sep and calls _from_parsed_string. The result stores _drv (drive), _root, and _tail (list of path components) as slots.

# CPython: Lib/pathlib/_abc.py:105 PurePath.__new__
def __new__(cls, *args, **kwargs):
    paths = []
    for arg in args:
        ...
        paths.append(os.fspath(arg))
    path = cls._from_parsed_parts(drv, root, tail)
    return path

parent and parents

PurePath.parent returns _from_parsed_parts(drv, root, tail[:-1]). The _PathParents sequence wraps this with __getitem__ and __len__ for path.parents[2] style access.

relative_to

relative_to compares leading components. In Python 3.12+ it also accepts walk_up=True which inserts .. components to walk up out of the base before descending.

# CPython: Lib/pathlib/_abc.py:400 PurePath.relative_to
def relative_to(self, other, /, *_deprecated, walk_up=False):
    other = self.with_segments(other, *_deprecated)
    ...
    if walk_up:
        parts = ['..'] * (len(other._tail) - anchor_len) + self._tail[anchor_len:]
    ...

match

match converts a glob pattern to a regex using re.compile and matches against the string representation. The case_sensitive parameter (default: platform-dependent) was added in Python 3.12.

gopy notes

Not yet ported. pathlib depends on os.path and os.fspath, which must be available first. The PurePath string manipulation subset can be ported independently of the I/O methods. Planned path: module/pathlib/.