# `os.path` --- Common pathname manipulations

Source code: Lib/genericpath.py, Lib/posixpath.py (for POSIX) and Lib/ntpath.py (for Windows).

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 strings, or bytes, or any object implementing the `os.PathLike` protocol.

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.)

Voir aussi

Le module `pathlib` offre une représentation objet de haut niveau des chemins.

Note

Toutes ces fonctions n'acceptent que des chaînes d'octets ou des chaînes de caractères en tant que paramètres. Le résultat est un objet du même type si un chemin ou un nom de fichier est renvoyé.

Note

Comme les différents systèmes d'exploitation ont des conventions de noms de chemins différentes, il existe plusieurs versions de ce module dans la bibliothèque standard. Le module `os.path` est toujours le module de chemin adapté au système d'exploitation sur lequel Python tourne, et donc adapté pour les chemins locaux. Cependant, vous pouvez également importer et utiliser les modules individuels si vous voulez manipuler un chemin qui est toujours dans l'un des différents formats. Ils ont tous la même interface :

- `posixpath` for UNIX-style paths

- `ntpath` for Windows paths

Modifié dans la version 3.8: `exists()`, `lexists()`, `isdir()`, `isfile()`, `islink()`, and `ismount()` now return `False` instead of raising an exception for paths that contain characters or bytes unrepresentable at the OS level.

os.path.abspath(path)

  Return a normalized absolutized version of the pathname path. On most platforms, this is equivalent to calling `normpath(join(os.getcwd(), path))`.

  Voir aussi

  `os.path.join()` and `os.path.normpath()`.

  Modifié dans la version 3.6: Accepte un path-like object.

os.path.basename(path, /)

  Renvoie le nom de base du chemin d'accès path. C'est le second élément de la paire renvoyée en passant path à la fonction `split()`. Notez que le résultat de cette fonction est différent de celui du programme Unix basename ; là où basename pour `'/foo/bar/'` renvoie `'bar'`, la fonction `basename()` renvoie une chaîne vide (`''`).

  Modifié dans la version 3.6: Accepte un path-like object.

os.path.commonpath(paths)

  Return the longest common sub-path of each pathname in the iterable paths. Raise `ValueError` if paths contain both absolute and relative pathnames, if paths are on different drives, or if paths is empty. Unlike `commonprefix()`, this returns a valid path.

  Ajouté dans la version 3.5.

  Modifié dans la version 3.6: Accepts a sequence of path-like objects.

  Modifié dans la version 3.13: Any iterable can now be passed, rather than just sequences.

os.path.commonprefix(list, /)

  Return the longest string prefix (taken character-by-character) that is a prefix of all strings in list. If list is empty, return the empty string (`''`).

  Avertissement

  This function may return invalid paths because it works a character at a time. If you need a common path prefix, then the algorithm implemented in this function is not secure. Use `commonpath()` for finding a common path prefix.

      >>> os.path.commonprefix(['/usr/lib', '/usr/local/lib'])
      '/usr/l'

      >>> os.path.commonpath(['/usr/lib', '/usr/local/lib'])
      '/usr'

  Modifié dans la version 3.6: Accepte un 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()`.

  Modifié dans la version 3.6: Accepte un 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.

  Modifié dans la version 3.3: path can now be an integer: `True` is returned if it is an open file descriptor, `False` otherwise.

  Modifié dans la version 3.6: Accepte un path-like object.

os.path.lexists(path)

  Return `True` if path refers to an existing path, including broken symbolic links. Equivalent to `exists()` on platforms lacking `os.lstat()`.

  Modifié dans la version 3.6: Accepte un 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, `USERPROFILE` will be used if set, otherwise a combination of `HOMEPATH` and `HOMEDRIVE` will be used. An initial `~user` is handled by checking that the last directory component of the current user's home directory matches `USERNAME`, and replacing it if so.

  If the expansion fails or if the path does not begin with a tilde, the path is returned unchanged.

  Modifié dans la version 3.6: Accepte un path-like object.

  Modifié dans la version 3.8: No longer uses `HOME` on Windows.

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}`.

  Modifié dans la version 3.6: Accepte un path-like object.

os.path.getatime(path, /)

  Return the time of last access of path. The return value is a floating-point number giving the number of seconds since the epoch (see the `time` module). Raise `OSError` if the file does not exist or is inaccessible.

os.path.getmtime(path, /)

  Return the time of last modification of path. The return value is a floating-point number giving the number of seconds since the epoch (see the `time` module). Raise `OSError` if the file does not exist or is inaccessible.

  Modifié dans la version 3.6: Accepte un 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.

  Modifié dans la version 3.6: Accepte un 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.

  Modifié dans la version 3.6: Accepte un 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 two (back)slashes, or a drive letter, colon, and (back)slash together.

  Voir aussi

  `abspath()`

  Modifié dans la version 3.6: Accepte un path-like object.

  Modifié dans la version 3.13: On Windows, returns `False` if the given path starts with exactly one (back)slash.

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.

  Modifié dans la version 3.6: Accepte un 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.

  Modifié dans la version 3.6: Accepte un path-like object.

os.path.isjunction(path)

  Return `True` if path refers to an `existing` directory entry that is a junction. Always return `False` if junctions are not supported on the current platform.

  Ajouté dans la version 3.12.

os.path.islink(path)

  Return `True` if path refers to an `existing` directory entry that is a symbolic link. Always `False` if symbolic links are not supported by the Python runtime.

  Modifié dans la version 3.6: Accepte un 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. It is not able to reliably detect bind mounts on the same filesystem. On Linux systems, it will always return `True` for btrfs subvolumes, even if they aren't mount points. 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.

  Modifié dans la version 3.4: Added support for detecting non-root mount points on Windows.

  Modifié dans la version 3.6: Accepte un path-like object.

os.path.isdevdrive(path)

  Return `True` if pathname path is located on a Windows Dev Drive. A Dev Drive is optimized for developer scenarios, and offers faster performance for reading and writing files. It is recommended for use for source code, temporary build directories, package caches, and other IO-intensive operations.

  May raise an error for an invalid path, for example, one without a recognizable drive, but returns `False` on platforms that do not support Dev Drives. See the Windows documentation for information on enabling and creating Dev Drives.

  Ajouté dans la version 3.12.

  Modifié dans la version 3.13: The function is now available on all platforms, and will always return `False` on those that have no support for Dev Drives

os.path.isreserved(path)

  Return `True` if path is a reserved pathname on the current system.

  On Windows, reserved filenames include those that end with a space or dot; those that contain colons (i.e. file streams such as "name:stream"), wildcard characters (i.e. `'*?"<>'`), pipe, or ASCII control characters; as well as DOS device names such as "NUL", "CON", "CONIN$", "CONOUT$", "AUX", "PRN", "COM1", and "LPT1".

  Note

  This function approximates rules for reserved paths on most Windows systems. These rules change over time in various Windows releases. This function may be updated in future Python releases as changes to the rules become broadly available.

  Disponibilité: Windows.

  Ajouté dans la version 3.13.

os.path.join(path, /, *paths)

  Join one or more path segments intelligently. The return value is the concatenation of path and all members of *paths, with exactly one directory separator following each non-empty part, except the last. That is, the result will only end in a separator if the last part is either empty or ends in a separator.

  If a segment is an absolute path (which on Windows requires both a drive and a root), then all previous segments are ignored and joining continues from the absolute path segment. On Linux, for example:

      >>> os.path.join('/home/foo', 'bar')
      '/home/foo/bar'
      >>> os.path.join('/home/foo', '/home/bar')
      '/home/bar'

  On Windows, the drive is not reset when a rooted path segment (e.g., `r'\foo'`) is encountered. If a segment is on a different drive or is an absolute path, all previous segments are ignored and the drive is reset. For example:

      >>> os.path.join('c:\\', 'foo')
      'c:\\foo'
      >>> os.path.join('c:\\foo', 'd:\\bar')
      'd:\\bar'

  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`.

  Modifié dans la version 3.6: Accepts a path-like object for path and paths.

os.path.normcase(path, /)

  Normalize the case of a pathname. On Windows, convert all characters in the pathname to lowercase, and also convert forward slashes to backward slashes. On other operating systems, return the path unchanged.

  Modifié dans la version 3.6: Accepte un 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()`.

  Note

  On POSIX systems, in accordance with IEEE Std 1003.1 2013 Edition; 4.13 Pathname Resolution, if a pathname begins with exactly two slashes, the first component following the leading characters may be interpreted in an implementation-defined manner, although more than two leading characters shall be treated as a single character.

  Modifié dans la version 3.6: Accepte un path-like object.

os.path.realpath(path, /, *, strict=False)

  Return the canonical path of the specified filename, eliminating any symbolic links encountered in the path (if they are supported by the operating system). On Windows, this function will also resolve MS-DOS (also called 8.3) style names such as `C:\\PROGRA~1` to `C:\\Program Files`.

  By default, the path is evaluated up to the first component that does not exist, is a symlink loop, or whose evaluation raises `OSError`. All such components are appended unchanged to the existing part of the path.

  Some errors that are handled this way include "access denied", "not a directory", or "bad argument to internal function". Thus, the resulting path may be missing or inaccessible, may still contain links or loops, and may traverse non-directories.

  This behavior can be modified by keyword arguments:

  If strict is `True`, the first error encountered when evaluating the path is re-raised. In particular, `FileNotFoundError` is raised if path does not exist, or another `OSError` if it is otherwise inaccessible.

  If strict is `os.path.ALLOW_MISSING`, errors other than `FileNotFoundError` are re-raised (as with `strict=True`). Thus, the returned path will not contain any symbolic links, but the named file and some of its parent directories may be missing.

  Note

  This function emulates the operating system's procedure for making a path canonical, which differs slightly between Windows and UNIX with respect to how links and subsequent path components interact.

  Operating system APIs make paths canonical as needed, so it's not normally necessary to call this function.

  Modifié dans la version 3.6: Accepte un path-like object.

  Modifié dans la version 3.8: Symbolic links and junctions are now resolved on Windows.

  Modifié dans la version 3.10: The strict parameter was added.

  Modifié dans la version 3.14: The `ALLOW_MISSING` value for the strict parameter was added.

os.path.ALLOW_MISSING

  Special value used for the strict argument in `realpath()`.

  Ajouté dans la version 3.14.

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. On Windows, `ValueError` is raised when path and start are on different drives.

  start defaults to `os.curdir`.

  Modifié dans la version 3.6: Accepte un 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.

  Modifié dans la version 3.2: Prise en charge de Windows.

  Modifié dans la version 3.4: Windows now uses the same implementation as all other platforms.

  Modifié dans la version 3.6: Accepte un path-like object.

os.path.sameopenfile(fp1, fp2)

  Return `True` if the file descriptors fp1 and fp2 refer to the same file.

  Modifié dans la version 3.2: Prise en charge de Windows.

  Modifié dans la version 3.6: Accepte un 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()`.

  Modifié dans la version 3.4: Prise en charge de Windows.

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 `join()`, `dirname()` and `basename()`.

  Modifié dans la version 3.6: Accepte un 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:

      >>> splitdrive("c:/dir")
      ("c:", "/dir")

  If the path contains a UNC path, drive will contain the host name and share:

      >>> splitdrive("//host/computer/dir")
      ("//host/computer", "/dir")

  Modifié dans la version 3.6: Accepte un path-like object.

os.path.splitroot(path, /)

  Split the pathname path into a 3-item tuple `(drive, root, tail)` where drive is a device name or mount point, root is a string of separators after the drive, and tail is everything after the root. Any of these items may be the empty string. In all cases, `drive + root + tail` will be the same as path.

  On POSIX systems, drive is always empty. The root may be empty (if path is relative), a single forward slash (if path is absolute), or two forward slashes (implementation-defined per IEEE Std 1003.1-2017; 4.13 Pathname Resolution.) For example:

      >>> splitroot('/home/sam')
      ('', '/', 'home/sam')
      >>> splitroot('//home/sam')
      ('', '//', 'home/sam')
      >>> splitroot('///home/sam')
      ('', '/', '//home/sam')

  On Windows, drive may be empty, a drive-letter name, a UNC share, or a device name. The root may be empty, a forward slash, or a backward slash. For example:

      >>> splitroot('C:/Users/Sam')
      ('C:', '/', 'Users/Sam')
      >>> splitroot('//Server/Share/Users/Sam')
      ('//Server/Share', '/', 'Users/Sam')

  Ajouté dans la version 3.12.

os.path.splitext(path, /)

  Split the pathname path into a pair `(root, ext)` such that `root + ext == path`, and the extension, ext, is empty or begins with a period and contains at most one period.

  If the path contains no extension, ext will be `''`:

      >>> splitext('bar')
      ('bar', '')

  If the path contains an extension, then ext will be set to this extension, including the leading period. Note that previous periods will be ignored:

      >>> splitext('foo.bar.exe')
      ('foo.bar', '.exe')
      >>> splitext('/foo/bar.exe')
      ('/foo/bar', '.exe')

  Leading periods of the last component of the path are considered to be part of the root:

      >>> splitext('.cshrc')
      ('.cshrc', '')
      >>> splitext('/foo/....jpg')
      ('/foo/....jpg', '')

  Modifié dans la version 3.6: Accepte un path-like object.

os.path.supports_unicode_filenames

  `True` if arbitrary Unicode strings can be used as file names (within limitations imposed by the file system).