"os.path" --- Common pathname manipulations
*******************************************

**Source code:** 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.)

Vedi anche: The "pathlib" module offers high-level path objects.

Nota:

  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.

Nota:

  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 paths

  * "ntpath" for Windows paths

Cambiato nella versione 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 the function
   "normpath()" as follows: "normpath(join(os.getcwd(), path))".

   Cambiato nella versione 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
   ("''").

   Cambiato nella versione 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* contain both absolute and
   relative pathnames, the *paths* are on the different drives or if
   *paths* is empty.  Unlike "commonprefix()", this returns a valid
   path.

   Availability: Unix, Windows.

   Nuovo nella versione 3.5.

   Cambiato nella versione 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 ("''").

   Nota:

     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'

   Cambiato nella versione 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()".

   Cambiato nella versione 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.

   Cambiato nella versione 3.3: *path* can now be an integer: "True"
   is returned if it is an  open file descriptor, "False" otherwise.

   Cambiato nella versione 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()".

   Cambiato nella versione 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, "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.

   Cambiato nella versione 3.6: Accepts a *path-like object*.

   Cambiato nella versione 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}".

   Cambiato nella versione 3.6: Accepts a *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.

   Cambiato nella versione 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.

   Cambiato nella versione 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.

   Cambiato nella versione 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.

   Cambiato nella versione 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.

   Cambiato nella versione 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.

   Cambiato nella versione 3.6: Accepts a *path-like object*.

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.

   Cambiato nella versione 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.  It is not
   able to reliably detect bind mounts on the same filesystem.  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.

   Nuovo nella versione 3.4: Support for detecting non-root mount
   points on Windows.

   Cambiato nella versione 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 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".

   Cambiato nella versione 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.

   Cambiato nella versione 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()".

   Nota:

        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.

     Cambiato nella versione 3.6: Accepts a *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).

   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.

   Nota:

     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.

   Cambiato nella versione 3.6: Accepts a *path-like object*.

   Cambiato nella versione 3.8: Symbolic links and junctions are now
   resolved on Windows.

   Cambiato nella versione 3.9.23: The *strict* parameter was added.

   Cambiato nella versione 3.9.23 (unreleased): The "ALLOW_MISSING"
   value for the *strict* parameter was added.

os.path.ALLOW_MISSING

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

   Nuovo nella versione 3.9.23 (unreleased).

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".

   Availability: Unix, Windows.

   Cambiato nella versione 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.

   Cambiato nella versione 3.2: Added Windows support.

   Cambiato nella versione 3.4: Windows now uses the same
   implementation as all other platforms.

   Cambiato nella versione 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.

   Cambiato nella versione 3.2: Added Windows support.

   Cambiato nella versione 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.

   Cambiato nella versione 3.4: Added Windows support.

   Cambiato nella versione 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()".

   Cambiato nella versione 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:

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

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

   Cambiato nella versione 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 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', '')

   Cambiato nella versione 3.6: Accepts a *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).
