Lib/pathlib/__init__.py

Source:

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

Lib/pathlib/__init__.py defines PurePath, PurePosixPath, PureWindowsPath, Path, PosixPath, and WindowsPath. PurePath is immutable and provides parsing, normalization, and the / operator for joining. Path adds filesystem operations (stat, open, mkdir, glob, rename, etc.).

Map

Lines	Symbol	Role
1-80	imports, _PathParents	Imports; the parents sequence proxy
81-400	PurePath	Immutable path: parts, name, stem, suffix, //operator, comparison
401-600	PurePosixPath, PureWindowsPath	Platform-specific pure paths
601-900	Path	Filesystem path: stat, open, read_text, write_text, mkdir, unlink
901-1100	Path.glob, Path.walk	Recursive directory traversal
1101-1200	PosixPath, WindowsPath	Concrete platform subclasses

Reading

PurePath: immutable path arithmetic

PurePath stores a normalized tuple of path parts. The / operator calls __truediv__ which creates a new PurePath from the joined string.

# CPython: Lib/pathlib/__init__.py:81 PurePath.__truediv__
class PurePath:
    def __truediv__(self, key):
        try:
            return self._from_parsed_parts(self._drv, self._root,
                                           self._parts + type(self)(key)._parts)
        except TypeError:
            return NotImplemented

parts returns a tuple; name is the final component; stem strips the final suffix; suffix is the extension including the dot.

Path.open and filesystem ops

Path.open(mode, buffering, encoding, ...) delegates to io.open(str(self), ...). read_text and write_text are convenience wrappers. stat() calls os.stat(self).

# CPython: Lib/pathlib/__init__.py:601 Path.open
def open(self, mode='r', buffering=-1, encoding=None,
         errors=None, newline=None):
    return self._accessor.open(self, flags, mode)

glob and walk

Path.glob(pattern) calls _WildcardSelector or _RecursiveWildcardSelector depending on whether ** is present. In CPython 3.12 the glob implementation was rewritten to use os.scandir instead of os.listdir, improving performance and enabling follow_symlinks control.

Path.walk() (added in 3.12) mirrors os.walk but yields (dirpath, dirnames, filenames) tuples where each element is a Path.

gopy notes

Not yet ported. The planned package path is module/pathlib/. Go's path/filepath package covers most of the filesystem operations; filepath.Join, filepath.Glob, and filepath.WalkDir map to the corresponding Path methods.