Lib/pathlib/_abc.py

Source:

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

pathlib._abc (extracted in Python 3.12) defines the abstract base classes for PurePath and Path. The concrete classes (PurePosixPath, PureWindowsPath, PosixPath, WindowsPath) are in pathlib/_local.py.

Map

Lines	Symbol	Role
1-80	PurePath.__new__, _str_normcase_cached, _hash	Construction and caching
81-200	PurePath properties	parts, drive, root, anchor, parent, parents, name, suffix, suffixes, stem
201-350	PurePath methods	relative_to, is_relative_to, match, with_name, with_stem, with_suffix, with_segments, joinpath, / operator
351-480	Path abstract I/O methods	stat, open, read_bytes, read_text, write_bytes, write_text, iterdir, glob, rglob
481-580	Path.mkdir, Path.rename, Path.unlink, Path.symlink_to, Path.hardlink_to	Filesystem mutation

Reading

PurePath construction and parsing

PurePath.__new__ splits the path string into drive, root, and parts using the flavor-specific parser (_PosixFlavour or _WindowsFlavour).

# CPython: Lib/pathlib/_abc.py:200 PurePath.__new__
def __new__(cls, *args, **kwargs):
    ...
    obj = object.__new__(cls)
    obj._raw_paths = args
    return obj

@property
def _str_normcase(self):
    ...
    return self._flavour.casefold(str(self))

Parsing is deferred until properties are first accessed, cached in _parts_normcase_cached.

relative_to

# CPython: Lib/pathlib/_abc.py:338 PurePath.relative_to
def relative_to(self, other, /, *_deprecated, walk_up=False):
    other = other if isinstance(other, PurePath) else self.with_segments(other)
    for step, path in enumerate([other] + list(other.parents)):
        if self.is_relative_to(path):
            break
    else:
        raise ValueError(f"{str(self)!r} is not relative to {str(other)!r}")
    parts = ['..'] * step + list(self.parts[len(path.parts):])
    return self.with_segments(*parts)

walk_up=True (Python 3.12) allows relative_to to generate .. components when the two paths share only a common ancestor.

glob and rglob

Path.glob(pattern) returns an iterator of matching paths. For patterns with **, it recurses via os.scandir. The implementation handles filesystem case sensitivity based on the OS.

Path.open

# CPython: Lib/pathlib/_abc.py:430 Path.open
def open(self, mode='r', buffering=-1, encoding=None, errors=None, newline=None):
    return self._accessor.open(self, mode, buffering, encoding, errors, newline)

Delegates to the OS accessor, which calls io.open(str(self), ...).

gopy notes

The gopy equivalent is module/pathlib/. PurePath string manipulation maps to Go's path/filepath functions. The concrete Path type wraps os.Open, os.Stat, os.ReadDir, etc. The glob implementation needs a filepath.WalkDir-based recursive matcher.