os.path — Common pathname manipulations¶Source code: Lib/posixpath.py (for POSIX), Lib/ntpath.py (for Windows NT), and Lib/macpath.py (for Macintosh)
This module implements some useful functions on pathnames. To read or
write files see open(), and for accessing the filesystem see the
os module. The path parameters can be passed as either strings,
or bytes. Applications are encouraged to represent file names as
(Unicode) character strings. Unfortunately, some file names may not be
representable as strings on Unix, so applications that need to support
arbitrary file names on Unix should use bytes objects to represent
path names. Vice versa, using bytes objects cannot represent all file
names on Windows (in the standard mbcs encoding), hence Windows
applications should use string objects to access all files.
Unlike a unix shell, Python does not do any automatic path expansions.
Functions such as expanduser() and expandvars() can be invoked
explicitly when an application desires shell-like path expansion. (See also
the glob module.)
See also
The pathlib module offers high-level path objects.
Note
All of these functions accept either only bytes or only string objects as their parameters. The result is an object of the same type, if a path or file name is returned.
Note
Since different operating systems have different path name conventions, there
are several versions of this module in the standard library. The
os.path module is always the path module suitable for the operating
system Python is running on, and therefore usable for local paths. However,
you can also import and use the individual modules if you want to manipulate
a path that is always in one of the different formats. They all have the
same interface:
posixpath for UNIX-style pathsntpath for Windows pathsmacpath for old-style MacOS pathsos.path.abspath(path)¶Return a normalized absolutized version of the pathname path. On most
platforms, this is equivalent to calling the function normpath() as
follows: normpath(join(os.getcwd(), path)).
Changed in version 3.6: Accepts a path-like object.
os.path.basename(path)¶Return the base name of pathname path. This is the second element of the
pair returned by passing path to the function split(). Note that
the result of this function is different
from the Unix basename program; where basename for
'/foo/bar/' returns 'bar', the basename() function returns an
empty string ('').
Changed in version 3.6: Accepts a path-like object.
os.path.commonpath(paths)¶Return the longest common sub-path of each pathname in the sequence
paths. Raise ValueError if paths contains both absolute and relative
pathnames, or if paths is empty. Unlike commonprefix(), this
returns a valid path.
Availability: Unix, Windows
New in version 3.5.
Changed in version 3.6: Accepts a sequence of path-like objects.
os.path.commonprefix(list)¶Return the longest path prefix (taken character-by-character) that is a
prefix of all paths in list. If list is empty, return the empty string
('').
Note
This function may return invalid paths because it works a
character at a time. To obtain a valid path, see
commonpath().
>>> os.path.commonprefix(['/usr/lib', '/usr/local/lib'])
'/usr/l'
>>> os.path.commonpath(['/usr/lib', '/usr/local/lib'])
'/usr'
Changed in version 3.6: Accepts a path-like object.
os.path.dirname(path)¶Return the directory name of pathname path. This is the first element of
the pair returned by passing path to the function split().
Changed in version 3.6: Accepts a path-like object.
os.path.exists(path)¶Return True if path refers to an existing path or an open
file descriptor. Returns False for broken symbolic links. On
some platforms, this function may return False if permission is
not granted to execute os.stat() on the requested file, even
if the path physically exists.
Changed in version 3.3: path can now be an integer: True is returned if it is an
open file descriptor, False otherwise.
Changed in version 3.6: Accepts a path-like object.
os.path.lexists(path)¶Return True if path refers to an existing path. Returns True for
broken symbolic links. Equivalent to exists() on platforms lacking
os.lstat().
Changed in version 3.6: Accepts a path-like object.
os.path.expanduser(path)¶On Unix and Windows, return the argument with an initial component of ~ or
~user replaced by that user‘s home directory.
On Unix, an initial ~ is replaced by the environment variable HOME
if it is set; otherwise the current user’s home directory is looked up in the
password directory through the built-in module pwd. An initial ~user
is looked up directly in the password directory.
On Windows, HOME and USERPROFILE will be used if set,
otherwise a combination of HOMEPATH and HOMEDRIVE will be
used. An initial ~user is handled by stripping the last directory component
from the created user path derived above.
If the expansion fails or if the path does not begin with a tilde, the path is returned unchanged.
Changed in version 3.6: Accepts a path-like object.
os.path.expandvars(path)¶Return the argument with environment variables expanded. Substrings of the form
$name or ${name} are replaced by the value of environment variable
name. Malformed variable names and references to non-existing variables are
left unchanged.
On Windows, %name% expansions are supported in addition to $name and
${name}.
Changed in version 3.6: Accepts a path-like object.
os.path.getatime(path)¶Return the time of last access of path. The return value is a number giving
the number of seconds since the epoch (see the time module). Raise
OSError if the file does not exist or is inaccessible.
If os.stat_float_times() returns True, the result is a floating point
number.
os.path.getmtime(path)¶Return the time of last modification of path. The return value is a number
giving the number of seconds since the epoch (see the time module).
Raise OSError if the file does not exist or is inaccessible.
If os.stat_float_times() returns True, the result is a floating point
number.
Changed in version 3.6: Accepts a path-like object.
os.path.getctime(path)¶Return the system’s ctime which, on some systems (like Unix) is the time of the
last metadata change, and, on others (like Windows), is the creation time for path.
The return value is a number giving the number of seconds since the epoch (see
the time module). Raise OSError if the file does not exist or
is inaccessible.
Changed in version 3.6: Accepts a path-like object.
os.path.getsize(path)¶Return the size, in bytes, of path. Raise OSError if the file does
not exist or is inaccessible.
Changed in version 3.6: Accepts a path-like object.
os.path.isabs(path)¶Return True if path is an absolute pathname. On Unix, that means it
begins with a slash, on Windows that it begins with a (back)slash after chopping
off a potential drive letter.
Changed in version 3.6: Accepts a path-like object.
os.path.isfile(path)¶Return True if path is an existing regular file. This follows symbolic
links, so both islink() and isfile() can be true for the same path.
Changed in version 3.6: Accepts a path-like object.
os.path.isdir(path)¶Return True if path is an existing directory. This follows symbolic
links, so both islink() and isdir() can be true for the same path.
Changed in version 3.6: Accepts a path-like object.
os.path.islink(path)¶Return True if path refers to a directory entry that is a symbolic link.
Always False if symbolic links are not supported by the Python runtime.
Changed in version 3.6: Accepts a path-like object.
os.path.ismount(path)¶Return True if pathname path is a mount point: a point in a
file system where a different file system has been mounted. On POSIX, the
function checks whether path‘s parent, path/.., is on a different
device than path, or whether path/.. and path point to the same
i-node on the same device — this should detect mount points for all Unix
and POSIX variants. On Windows, a drive letter root and a share UNC are
always mount points, and for any other path GetVolumePathName is called
to see if it is different from the input path.
New in version 3.4: Support for detecting non-root mount points on Windows.
Changed in version 3.6: Accepts a path-like object.
os.path.join(path, *paths)¶Join one or more path components intelligently. The return value is the
concatenation of path and any members of *paths with exactly one
directory separator (os.sep) following each non-empty part except the
last, meaning that the result will only end in a separator if the last
part is empty. If a component is an absolute path, all previous
components are thrown away and joining continues from the absolute path
component.
On Windows, the drive letter is not reset when an absolute path component
(e.g., r'\foo') is encountered. If a component contains a drive
letter, all previous components are thrown away and the drive letter is
reset. Note that since there is a current directory for each drive,
os.path.join("c:", "foo") represents a path relative to the current
directory on drive C: (c:foo), not c:\foo.
Changed in version 3.6: Accepts a path-like object for path and paths.
os.path.normcase(path)¶Normalize the case of a pathname. On Unix and Mac OS X, this returns the
path unchanged; on case-insensitive filesystems, it converts the path to
lowercase. On Windows, it also converts forward slashes to backward slashes.
Raise a TypeError if the type of path is not str or bytes (directly
or indirectly through the os.PathLike interface).
Changed in version 3.6: Accepts a path-like object.
os.path.normpath(path)¶Normalize a pathname by collapsing redundant separators and up-level
references so that A//B, A/B/, A/./B and A/foo/../B all
become A/B. This string manipulation may change the meaning of a path
that contains symbolic links. On Windows, it converts forward slashes to
backward slashes. To normalize case, use normcase().
Changed in version 3.6: Accepts a path-like object.
os.path.realpath(path)¶Return the canonical path of the specified filename, eliminating any symbolic links encountered in the path (if they are supported by the operating system).
Changed in version 3.6: Accepts a path-like object.
os.path.relpath(path, start=os.curdir)¶Return a relative filepath to path either from the current directory or from an optional start directory. This is a path computation: the filesystem is not accessed to confirm the existence or nature of path or start.
start defaults to os.curdir.
Availability: Unix, Windows.
Changed in version 3.6: Accepts a path-like object.
os.path.samefile(path1, path2)¶Return True if both pathname arguments refer to the same 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.
Availability: Unix, Windows.
Changed in version 3.2: Added Windows support.
Changed in version 3.4: Windows now uses the same implementation as all other platforms.
Changed in version 3.6: Accepts a path-like object.
os.path.sameopenfile(fp1, fp2)¶Return True if the file descriptors fp1 and fp2 refer to the same file.
Availability: Unix, Windows.
Changed in version 3.2: Added Windows support.
Changed in version 3.6: Accepts a path-like object.
os.path.samestat(stat1, stat2)¶Return True if the stat tuples stat1 and stat2 refer to the same file.
These structures may have been returned by os.fstat(),
os.lstat(), or os.stat(). This function implements the
underlying comparison used by samefile() and sameopenfile().
Availability: Unix, Windows.
Changed in version 3.4: Added Windows support.
Changed in version 3.6: Accepts a path-like object.
os.path.split(path)¶Split the pathname path into a pair, (head, tail) where tail is the
last pathname component and head is everything leading up to that. The
tail part will never contain a slash; if path ends in a slash, tail
will be empty. If there is no slash in path, head will be empty. If
path is empty, both head and tail are empty. Trailing slashes are
stripped from head unless it is the root (one or more slashes only). In
all cases, join(head, tail) returns a path to the same location as path
(but the strings may differ). Also see the functions dirname() and
basename().
Changed in version 3.6: Accepts a path-like object.
os.path.splitdrive(path)¶Split the pathname path into a pair (drive, tail) where drive is either
a mount point or the empty string. On systems which do not use drive
specifications, drive will always be the empty string. In all cases, drive
+ tail will be the same as path.
On Windows, splits a pathname into drive/UNC sharepoint and relative path.
If the path contains a drive letter, drive will contain everything
up to and including the colon.
e.g. splitdrive("c:/dir") returns ("c:", "/dir")
If the path contains a UNC path, drive will contain the host name
and share, up to but not including the fourth separator.
e.g. splitdrive("//host/computer/dir") returns ("//host/computer", "/dir")
Changed in version 3.6: Accepts a path-like object.
os.path.splitext(path)¶Split the pathname path into a pair (root, ext) such that root + ext ==
path, and ext is empty or begins with a period and contains at most one
period. Leading periods on the basename are ignored; splitext('.cshrc')
returns ('.cshrc', '').
Changed in version 3.6: Accepts a path-like object.
os.path.splitunc(path)¶Deprecated since version 3.1: Use splitdrive instead.
Split the pathname path into a pair (unc, rest) so that unc is the UNC
mount point (such as r'\\host\mount'), if present, and rest the rest of
the path (such as r'\path\file.ext'). For paths containing drive letters,
unc will always be the empty string.
Availability: Windows.
os.path.supports_unicode_filenames¶True if arbitrary Unicode strings can be used as file names (within limitations
imposed by the file system).