Lib/posixpath.py (part 2)

Source:

cpython 3.14 @ ab2d84fe1023/Lib/posixpath.py ↗

This annotation covers the predicate and metadata functions. See modules_posixpath_detail for join, split, realpath, expanduser, and expandvars.

Map

Lines	Symbol	Role
1-40	isabs	True if path starts with /
41-100	isfile / isdir / islink	File type predicates via stat / lstat
101-160	lexists	lstat without following symlinks
161-220	samefile	Compare two paths via os.stat device+inode
221-300	getsize / getmtime / getatime	File metadata shortcuts
301-400	normpath	Collapse ., .., and double slashes
401-550	normcase	No-op on POSIX (case-sensitive filesystem)

Reading

isfile / isdir

# CPython: Lib/posixpath.py:180 isfile
def isfile(path):
    """Return True if path is an existing regular file."""
    try:
        st = os.stat(path)
    except (OSError, ValueError):
        return False
    return stat.S_ISREG(st.st_mode)

def isdir(path):
    try:
        st = os.stat(path)
    except (OSError, ValueError):
        return False
    return stat.S_ISDIR(st.st_mode)

isfile follows symlinks (uses stat). islink uses lstat:

def islink(path):
    try:
        st = os.lstat(path)
    except (OSError, ValueError):
        return False
    return stat.S_ISLNK(st.st_mode)

samefile

# CPython: Lib/posixpath.py:238 samefile
def samefile(f1, f2):
    """True if f1 and f2 refer to the same file (same device+inode)."""
    s1 = os.stat(f1)
    s2 = os.stat(f2)
    return os.path.samestat(s1, s2)

def samestat(s1, s2):
    return s1.st_ino == s2.st_ino and s1.st_dev == s2.st_dev

normpath

# CPython: Lib/posixpath.py:320 normpath
def normpath(path):
    """Normalize path: collapse // and . and .."""
    if isinstance(path, bytes):
        sep = b'/'
        dot = b'.'
    else:
        sep = '/'
        dot = '.'
    initial_slashes = path.startswith(sep)
    comps = path.split(sep)
    new_comps = []
    for comp in comps:
        if comp in ('', dot):
            continue
        if comp != '..':
            new_comps.append(comp)
        elif not initial_slashes and not new_comps:
            new_comps.append(comp)
        elif new_comps and new_comps[-1] == '..':
            new_comps.append(comp)
        elif new_comps:
            new_comps.pop()
    comps = new_comps
    path = sep.join(comps)
    if initial_slashes:
        path = sep * initial_slashes + path
    return path or dot

getmtime

# CPython: Lib/posixpath.py:410 getmtime
def getmtime(filename):
    """Return last modification time as a float (Unix timestamp)."""
    return os.stat(filename).st_mtime

gopy notes

posixpath is pure Python. isfile/isdir call os.stat which uses syscall.Stat. samefile compares st_ino and st_dev fields from os.stat_result. normpath is pure string manipulation.