"""

Path operations common to more than one OS

Do not use directly. The OS specific modules import the appropriate

functions from this module themselves.

"""

import os

import stat

__all__ = ['commonprefix', 'exists', 'getatime', 'getctime', 'getmtime',

'getsize', 'isdevdrive', 'isdir', 'isfile', 'isjunction', 'islink',

'lexists', 'samefile', 'sameopenfile', 'samestat', 'ALLOW_MISSING']

# Does a path exist?

# This is false for dangling symbolic links on systems that support them.

def exists(path):

"""Test whether a path exists. Returns False for broken symbolic links"""

try:

os.stat(path)

except (OSError, ValueError):

return False

return True

# Being true for dangling symbolic links is also useful.

def lexists(path):

"""Test whether a path exists. Returns True for broken symbolic links"""

try:

os.lstat(path)

except (OSError, ValueError):

return False

return True

# This follows symbolic links, so both islink() and isdir() can be true

# for the same path on systems that support symlinks

def isfile(path):

"""Test whether a path is a regular file"""

try:

st = os.stat(path)

except (OSError, ValueError):

return False

return stat.S_ISREG(st.st_mode)

# Is a path a directory?

# This follows symbolic links, so both islink() and isdir()

# can be true for the same path on systems that support symlinks

def isdir(s):

"""Return true if the pathname refers to an existing directory."""

try:

st = os.stat(s)

except (OSError, ValueError):

return False

return stat.S_ISDIR(st.st_mode)

# Is a path a symbolic link?

# This will always return false on systems where os.lstat doesn't exist.

def islink(path):

"""Test whether a path is a symbolic link"""

try:

st = os.lstat(path)

except (OSError, ValueError, AttributeError):

return False

return stat.S_ISLNK(st.st_mode)

# Is a path a junction?

def isjunction(path):

"""Test whether a path is a junction

Junctions are not supported on the current platform"""

os.fspath(path)

return False

def isdevdrive(path):

"""Determines whether the specified path is on a Windows Dev Drive.

Dev Drives are not supported on the current platform"""

os.fspath(path)

return False

def getsize(filename):

"""Return the size of a file, reported by os.stat()."""

return os.stat(filename).st_size

def getmtime(filename):

"""Return the last modification time of a file, reported by os.stat()."""

return os.stat(filename).st_mtime

def getatime(filename):

"""Return the last access time of a file, reported by os.stat()."""

return os.stat(filename).st_atime

def getctime(filename):

"""Return the metadata change time of a file, reported by os.stat()."""

return os.stat(filename).st_ctime

# Return the longest prefix of all list elements.

def commonprefix(m):

"Given a list of pathnames, returns the longest common leading component"

if not m: return ''

# Some people pass in a list of pathname parts to operate in an OS-agnostic

# fashion; don't try to translate in that case as that's an abuse of the

# API and they are already doing what they need to be OS-agnostic and so

# they most likely won't be using an os.PathLike object in the sublists.

if not isinstance(m[0], (list, tuple)):

m = tuple(map(os.fspath, m))

s1 = min(m)

s2 = max(m)

for i, c in enumerate(s1):

if c != s2[i]:

return s1[:i]

return s1

# Are two stat buffers (obtained from stat, fstat or lstat)

# describing the same file?

def samestat(s1, s2):

"""Test whether two stat buffers reference the same file"""

return (s1.st_ino == s2.st_ino and

s1.st_dev == s2.st_dev)

# Are two filenames really pointing to the same file?

def samefile(f1, f2):

"""Test whether two pathnames reference the same actual file or directory

This is determined by the device number and i-node number and

raises an exception if an os.stat() call on either pathname fails.

"""

s1 = os.stat(f1)

s2 = os.stat(f2)

return samestat(s1, s2)

# Are two open files really referencing the same file?

# (Not necessarily the same file descriptor!)

def sameopenfile(fp1, fp2):

"""Test whether two open file objects reference the same file"""

s1 = os.fstat(fp1)

s2 = os.fstat(fp2)

return samestat(s1, s2)

# Split a path in root and extension.

# The extension is everything starting at the last dot in the last

# pathname component; the root is everything before that.

# It is always true that root + ext == p.

# Generic implementation of splitext, to be parametrized with

# the separators

def _splitext(p, sep, altsep, extsep):

"""Split the extension from a pathname.

Extension is everything from the last dot to the end, ignoring

leading dots. Returns "(root, ext)"; ext may be empty."""

# NOTE: This code must work for text and bytes strings.

sepIndex = p.rfind(sep)

if altsep:

altsepIndex = p.rfind(altsep)

sepIndex = max(sepIndex, altsepIndex)

dotIndex = p.rfind(extsep)

if dotIndex > sepIndex:

# skip all leading dots

filenameIndex = sepIndex + 1

while filenameIndex < dotIndex:

if p[filenameIndex:filenameIndex+1] != extsep:

return p[:dotIndex], p[dotIndex:]

filenameIndex += 1

return p, p[:0]

def _check_arg_types(funcname, *args):

hasstr = hasbytes = False

for s in args:

if isinstance(s, str):

hasstr = True

elif isinstance(s, bytes):

hasbytes = True

else:

raise TypeError(f'{funcname}() argument must be str, bytes, or '

f'os.PathLike object, not {s.__class__.__name__!r}') from None

if hasstr and hasbytes:

raise TypeError("Can't mix strings and bytes in path components") from None

# A singleton with a true boolean value.

@object.__new__

class ALLOW_MISSING:

"""Special value for use in realpath()."""

def __repr__(self):

return 'os.path.ALLOW_MISSING'

def __reduce__(self):

return self.__class__.__name__