"""Common operations on Posix pathnames.
Instead of importing this module directly, import os and refer to
this module as os.path. The "os.path" name is an alias for this
module on Posix systems; on other systems (e.g. Mac, Windows),
os.path provides the same operations in a manner specific to that
platform, and is an alias to another module (e.g. macpath, ntpath).
Some of this can actually be useful on non-Posix systems too, e.g.
for manipulation of the pathname component of URLs.
# Strings representing various path-related bits and pieces.
# These are primarily for export; internally, they are hardcoded.
# Should be set before imports for resolving cyclic dependency.
defpath = ':/bin:/usr/bin'
from genericpath import *
__all__ = ["normcase","isabs","join","splitdrive","split","splitext",
"basename","dirname","commonprefix","getsize","getmtime",
"getatime","getctime","islink","exists","lexists","isdir","isfile",
"ismount", "expanduser","expandvars","normpath","abspath",
"samefile","sameopenfile","samestat",
"curdir","pardir","sep","pathsep","defpath","altsep","extsep",
"devnull","realpath","supports_unicode_filenames","relpath",
if isinstance(path, bytes):
# Normalize the case of a pathname. Trivial in Posix, string.lower on Mac.
# On MS-DOS this may also turn slashes into backslashes; however, other
# normalizations (such as optimizing '../' away) are not allowed
# (another function should be defined to do that).
"""Normalize case of pathname. Has no effect under Posix"""
if not isinstance(s, (bytes, str)):
raise TypeError("normcase() argument must be str or bytes, "
"not '{}'".format(s.__class__.__name__))
# Return whether a path is absolute.
# Trivial in Posix, harder on the Mac or MS-DOS.
"""Test whether a path is absolute"""
# Ignore the previous parts if a part is absolute.
# Insert a '/' unless the first part is empty or already ends in '/'.
"""Join two or more pathname components, inserting '/' as needed.
If any component is an absolute path, all previous path components
will be discarded. An empty last part will result in a path that
ends with a separator."""
path[:0] + sep #23780: Ensure compatible data type even if p is null.
for b in map(os.fspath, p):
elif not path or path.endswith(sep):
except (TypeError, AttributeError, BytesWarning):
genericpath._check_arg_types('join', a, *p)
# Split a path in head (everything up to the last '/') and tail (the
# rest). If the path ends in '/', tail will be empty. If there is no
# '/' in the path, head will be empty.
# Trailing '/'es are stripped from head unless it is the root.
"""Split a pathname. Returns tuple "(head, tail)" where "tail" is
everything after the final slash. Either part may be empty."""
head, tail = p[:i], p[i:]
if head and head != sep*len(head):
# 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.
return genericpath._splitext(p, sep, None, extsep)
splitext.__doc__ = genericpath._splitext.__doc__
# Split a pathname into a drive specification and the rest of the
# path. Useful on DOS/Windows/NT; on Unix, the drive is always empty.
"""Split a pathname into drive and path. On Posix, drive is always
# Return the tail (basename) part of a path, same as split(path)[1].
"""Returns the final component of a pathname"""
# Return the head (dirname) part of a path, same as split(path)[0].
"""Returns the directory component of a pathname"""
if head and head != sep*len(head):
# Is a path a symbolic link?
# This will always return false on systems where os.lstat doesn't exist.
"""Test whether a path is a symbolic link"""
except (OSError, AttributeError):
return stat.S_ISLNK(st.st_mode)
# Being true for dangling symbolic links is also useful.
"""Test whether a path exists. Returns True for broken symbolic links"""
# Is a path a mount point?
# (Does this work for all UNIXes? Is it even guaranteed to work by Posix?)
"""Test whether a path is a mount point"""
# It doesn't exist -- so not a mount point. :-)
# A symlink can never be a mount point
if stat.S_ISLNK(s1.st_mode):
if isinstance(path, bytes):
parent = join(path, b'..')
parent = join(path, '..')
parent = realpath(parent)
return True # path/.. on a different device as path
return True # path/.. is the same i-node as path
# Expand paths beginning with '~' or '~user'.
# '~' means $HOME; '~user' means that user's home directory.
# If the path doesn't begin with '~', or if the user or $HOME is unknown,
# the path is returned unchanged (leaving error reporting to whatever
# function is called with the expanded path as argument).
# See also module 'glob' for expansion of *, ? and [...] in pathnames.
# (A function should also be defined to do full *sh-style environment
"""Expand ~ and ~user constructions. If user or $HOME is unknown,
if isinstance(path, bytes):
if not path.startswith(tilde):
if 'HOME' not in os.environ:
userhome = pwd.getpwuid(os.getuid()).pw_dir
# bpo-10496: if the current user identifier doesn't exist in the
# password database, return the path unchanged
userhome = os.environ['HOME']
if isinstance(name, bytes):
name = str(name, 'ASCII')
pwent = pwd.getpwnam(name)
# bpo-10496: if the user name from the path doesn't exist in the
# password database, return the path unchanged
if isinstance(path, bytes):
userhome = os.fsencode(userhome)
userhome = userhome.rstrip(root)
return (userhome + path[i:]) or root
# Expand paths containing shell variable substitutions.
# This expands the forms $variable and ${variable} only.
# Non-existent variables are left unchanged.
"""Expand shell variables of form $var and ${var}. Unknown variables
global _varprog, _varprogb
if isinstance(path, bytes):
_varprogb = re.compile(br'\$(\w+|\{[^}]*\})', re.ASCII)
search = _varprogb.search
environ = getattr(os, 'environb', None)
_varprog = re.compile(r'\$(\w+|\{[^}]*\})', re.ASCII)
if name.startswith(start) and name.endswith(end):
value = os.fsencode(os.environ[os.fsdecode(name)])
# Normalize a path, e.g. A//B, A/./B and A/foo/../B all become A/B.
# It should be understood that this may change the meaning of the path
# if it contains symbolic links!
"""Normalize path, eliminating double slashes, etc."""
if isinstance(path, bytes):
initial_slashes = path.startswith(sep)
# POSIX allows one or two initial slashes, but treats three or more
path.startswith(sep*2) and not path.startswith(sep*3)):
if (comp != dotdot or (not initial_slashes and not new_comps) or
(new_comps and new_comps[-1] == dotdot)):
path = sep*initial_slashes + path
"""Return an absolute path."""
if isinstance(path, bytes):
# Return a canonical path (i.e. the absolute location of a file on the
"""Return the canonical path of the specified filename, eliminating any
symbolic links encountered in the path."""
filename = os.fspath(filename)
path, ok = _joinrealpath(filename[:0], filename, {})
# Join two paths, normalizing and eliminating any symbolic links
# encountered in the second path.
def _joinrealpath(path, rest, seen):
if isinstance(path, bytes):
name, _, rest = rest.partition(sep)
if not name or name == curdir:
path = join(path, pardir, pardir)
newpath = join(path, name)
# Resolve the symbolic link
# The symlink is not resolved, so we must have a symlink loop.
# Return already resolved part + rest of the path unchanged.
return join(newpath, rest), False
seen[newpath] = None # not resolved symlink
path, ok = _joinrealpath(path, os.readlink(newpath), seen)
return join(path, rest), False
seen[newpath] = path # resolved symlink
supports_unicode_filenames = (sys.platform == 'darwin')
def relpath(path, start=None):
"""Return a relative version of a path"""
raise ValueError("no path specified")
if isinstance(path, bytes):
start_list = [x for x in abspath(start).split(sep) if x]
path_list = [x for x in abspath(path).split(sep) if x]
# Work out how much of the filepath is shared by start and path.
i = len(commonprefix([start_list, path_list]))
rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
except (TypeError, AttributeError, BytesWarning, DeprecationWarning):
genericpath._check_arg_types('relpath', path, start)
# Return the longest common sub-path of the sequence of paths given as input.
# The paths are not normalized before comparing them (this is the
# responsibility of the caller). Any trailing separator is stripped from the
"""Given a sequence of path names, returns the longest common sub-path."""
raise ValueError('commonpath() arg is an empty sequence')
paths = tuple(map(os.fspath, paths))
It is recommended that you Edit text format, this type of Fix handles quite a lot in one request
