1:mod:`shutil` --- High-level file operations
2============================================
3
4.. module:: shutil
5   :synopsis: High-level file operations, including copying.
6
7.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
8.. partly based on the docstrings
9
10**Source code:** :source:`Lib/shutil.py`
11
12.. index::
13   single: file; copying
14   single: copying files
15
16--------------
17
18The :mod:`shutil` module offers a number of high-level operations on files and
19collections of files.  In particular, functions are provided  which support file
20copying and removal. For operations on individual files, see also the
21:mod:`os` module.
22
23.. warning::
24
25   Even the higher-level file copying functions (:func:`shutil.copy`,
26   :func:`shutil.copy2`) cannot copy all file metadata.
27
28   On POSIX platforms, this means that file owner and group are lost as well
29   as ACLs.  On Mac OS, the resource fork and other metadata are not used.
30   This means that resources will be lost and file type and creator codes will
31   not be correct. On Windows, file owners, ACLs and alternate data streams
32   are not copied.
33
34
35.. _file-operations:
36
37Directory and files operations
38------------------------------
39
40.. function:: copyfileobj(fsrc, fdst[, length])
41
42   Copy the contents of the file-like object *fsrc* to the file-like object *fdst*.
43   The integer *length*, if given, is the buffer size. In particular, a negative
44   *length* value means to copy the data without looping over the source data in
45   chunks; by default the data is read in chunks to avoid uncontrolled memory
46   consumption. Note that if the current file position of the *fsrc* object is not
47   0, only the contents from the current file position to the end of the file will
48   be copied.
49
50
51.. function:: copyfile(src, dst, *, follow_symlinks=True)
52
53   Copy the contents (no metadata) of the file named *src* to a file named
54   *dst* and return *dst* in the most efficient way possible.
55   *src* and *dst* are path-like objects or path names given as strings.
56
57   *dst* must be the complete target file name; look at :func:`~shutil.copy`
58   for a copy that accepts a target directory path.  If *src* and *dst*
59   specify the same file, :exc:`SameFileError` is raised.
60
61   The destination location must be writable; otherwise, an :exc:`OSError`
62   exception will be raised. If *dst* already exists, it will be replaced.
63   Special files such as character or block devices and pipes cannot be
64   copied with this function.
65
66   If *follow_symlinks* is false and *src* is a symbolic link,
67   a new symbolic link will be created instead of copying the
68   file *src* points to.
69
70   .. audit-event:: shutil.copyfile src,dst shutil.copyfile
71
72   .. versionchanged:: 3.3
73      :exc:`IOError` used to be raised instead of :exc:`OSError`.
74      Added *follow_symlinks* argument.
75      Now returns *dst*.
76
77   .. versionchanged:: 3.4
78      Raise :exc:`SameFileError` instead of :exc:`Error`.  Since the former is
79      a subclass of the latter, this change is backward compatible.
80
81   .. versionchanged:: 3.8
82      Platform-specific fast-copy syscalls may be used internally in order to
83      copy the file more efficiently. See
84      :ref:`shutil-platform-dependent-efficient-copy-operations` section.
85
86.. exception:: SameFileError
87
88   This exception is raised if source and destination in :func:`copyfile`
89   are the same file.
90
91   .. versionadded:: 3.4
92
93
94.. function:: copymode(src, dst, *, follow_symlinks=True)
95
96   Copy the permission bits from *src* to *dst*.  The file contents, owner, and
97   group are unaffected.  *src* and *dst* are path-like objects or path names
98   given as strings.
99   If *follow_symlinks* is false, and both *src* and *dst* are symbolic links,
100   :func:`copymode` will attempt to modify the mode of *dst* itself (rather
101   than the file it points to).  This functionality is not available on every
102   platform; please see :func:`copystat` for more information.  If
103   :func:`copymode` cannot modify symbolic links on the local platform, and it
104   is asked to do so, it will do nothing and return.
105
106   .. audit-event:: shutil.copymode src,dst shutil.copymode
107
108   .. versionchanged:: 3.3
109      Added *follow_symlinks* argument.
110
111.. function:: copystat(src, dst, *, follow_symlinks=True)
112
113   Copy the permission bits, last access time, last modification time, and
114   flags from *src* to *dst*.  On Linux, :func:`copystat` also copies the
115   "extended attributes" where possible.  The file contents, owner, and
116   group are unaffected.  *src* and *dst* are path-like objects or path
117   names given as strings.
118
119   If *follow_symlinks* is false, and *src* and *dst* both
120   refer to symbolic links, :func:`copystat` will operate on
121   the symbolic links themselves rather than the files the
122   symbolic links refer to—reading the information from the
123   *src* symbolic link, and writing the information to the
124   *dst* symbolic link.
125
126   .. note::
127
128      Not all platforms provide the ability to examine and
129      modify symbolic links.  Python itself can tell you what
130      functionality is locally available.
131
132      * If ``os.chmod in os.supports_follow_symlinks`` is
133        ``True``, :func:`copystat` can modify the permission
134        bits of a symbolic link.
135
136      * If ``os.utime in os.supports_follow_symlinks`` is
137        ``True``, :func:`copystat` can modify the last access
138        and modification times of a symbolic link.
139
140      * If ``os.chflags in os.supports_follow_symlinks`` is
141        ``True``, :func:`copystat` can modify the flags of
142        a symbolic link.  (``os.chflags`` is not available on
143        all platforms.)
144
145      On platforms where some or all of this functionality
146      is unavailable, when asked to modify a symbolic link,
147      :func:`copystat` will copy everything it can.
148      :func:`copystat` never returns failure.
149
150      Please see :data:`os.supports_follow_symlinks`
151      for more information.
152
153   .. audit-event:: shutil.copystat src,dst shutil.copystat
154
155   .. versionchanged:: 3.3
156      Added *follow_symlinks* argument and support for Linux extended attributes.
157
158.. function:: copy(src, dst, *, follow_symlinks=True)
159
160   Copies the file *src* to the file or directory *dst*.  *src* and *dst*
161   should be :term:`path-like objects <path-like object>` or strings.  If
162   *dst* specifies a directory, the file will be copied into *dst* using the
163   base filename from *src*.  Returns the path to the newly created file.
164
165   If *follow_symlinks* is false, and *src* is a symbolic link,
166   *dst* will be created as a symbolic link.  If *follow_symlinks*
167   is true and *src* is a symbolic link, *dst* will be a copy of
168   the file *src* refers to.
169
170   :func:`~shutil.copy` copies the file data and the file's permission
171   mode (see :func:`os.chmod`).  Other metadata, like the
172   file's creation and modification times, is not preserved.
173   To preserve all file metadata from the original, use
174   :func:`~shutil.copy2` instead.
175
176   .. audit-event:: shutil.copyfile src,dst shutil.copy
177
178   .. audit-event:: shutil.copymode src,dst shutil.copy
179
180   .. versionchanged:: 3.3
181      Added *follow_symlinks* argument.
182      Now returns path to the newly created file.
183
184   .. versionchanged:: 3.8
185      Platform-specific fast-copy syscalls may be used internally in order to
186      copy the file more efficiently. See
187      :ref:`shutil-platform-dependent-efficient-copy-operations` section.
188
189.. function:: copy2(src, dst, *, follow_symlinks=True)
190
191   Identical to :func:`~shutil.copy` except that :func:`copy2`
192   also attempts to preserve file metadata.
193
194   When *follow_symlinks* is false, and *src* is a symbolic
195   link, :func:`copy2` attempts to copy all metadata from the
196   *src* symbolic link to the newly-created *dst* symbolic link.
197   However, this functionality is not available on all platforms.
198   On platforms where some or all of this functionality is
199   unavailable, :func:`copy2` will preserve all the metadata
200   it can; :func:`copy2` never raises an exception because it
201   cannot preserve file metadata.
202
203   :func:`copy2` uses :func:`copystat` to copy the file metadata.
204   Please see :func:`copystat` for more information
205   about platform support for modifying symbolic link metadata.
206
207   .. audit-event:: shutil.copyfile src,dst shutil.copy2
208
209   .. audit-event:: shutil.copystat src,dst shutil.copy2
210
211   .. versionchanged:: 3.3
212      Added *follow_symlinks* argument, try to copy extended
213      file system attributes too (currently Linux only).
214      Now returns path to the newly created file.
215
216   .. versionchanged:: 3.8
217      Platform-specific fast-copy syscalls may be used internally in order to
218      copy the file more efficiently. See
219      :ref:`shutil-platform-dependent-efficient-copy-operations` section.
220
221.. function:: ignore_patterns(*patterns)
222
223   This factory function creates a function that can be used as a callable for
224   :func:`copytree`\'s *ignore* argument, ignoring files and directories that
225   match one of the glob-style *patterns* provided.  See the example below.
226
227
228.. function:: copytree(src, dst, symlinks=False, ignore=None, \
229              copy_function=copy2, ignore_dangling_symlinks=False, \
230              dirs_exist_ok=False)
231
232   Recursively copy an entire directory tree rooted at *src* to a directory
233   named *dst* and return the destination directory. *dirs_exist_ok* dictates
234   whether to raise an exception in case *dst* or any missing parent directory
235   already exists.
236
237   Permissions and times of directories are copied with :func:`copystat`,
238   individual files are copied using :func:`~shutil.copy2`.
239
240   If *symlinks* is true, symbolic links in the source tree are represented as
241   symbolic links in the new tree and the metadata of the original links will
242   be copied as far as the platform allows; if false or omitted, the contents
243   and metadata of the linked files are copied to the new tree.
244
245   When *symlinks* is false, if the file pointed by the symlink doesn't
246   exist, an exception will be added in the list of errors raised in
247   an :exc:`Error` exception at the end of the copy process.
248   You can set the optional *ignore_dangling_symlinks* flag to true if you
249   want to silence this exception. Notice that this option has no effect
250   on platforms that don't support :func:`os.symlink`.
251
252   If *ignore* is given, it must be a callable that will receive as its
253   arguments the directory being visited by :func:`copytree`, and a list of its
254   contents, as returned by :func:`os.listdir`.  Since :func:`copytree` is
255   called recursively, the *ignore* callable will be called once for each
256   directory that is copied.  The callable must return a sequence of directory
257   and file names relative to the current directory (i.e. a subset of the items
258   in its second argument); these names will then be ignored in the copy
259   process.  :func:`ignore_patterns` can be used to create such a callable that
260   ignores names based on glob-style patterns.
261
262   If exception(s) occur, an :exc:`Error` is raised with a list of reasons.
263
264   If *copy_function* is given, it must be a callable that will be used to copy
265   each file. It will be called with the source path and the destination path
266   as arguments. By default, :func:`~shutil.copy2` is used, but any function
267   that supports the same signature (like :func:`~shutil.copy`) can be used.
268
269   .. audit-event:: shutil.copytree src,dst shutil.copytree
270
271   .. versionchanged:: 3.3
272      Copy metadata when *symlinks* is false.
273      Now returns *dst*.
274
275   .. versionchanged:: 3.2
276      Added the *copy_function* argument to be able to provide a custom copy
277      function.
278      Added the *ignore_dangling_symlinks* argument to silent dangling symlinks
279      errors when *symlinks* is false.
280
281   .. versionchanged:: 3.8
282      Platform-specific fast-copy syscalls may be used internally in order to
283      copy the file more efficiently. See
284      :ref:`shutil-platform-dependent-efficient-copy-operations` section.
285
286   .. versionadded:: 3.8
287      The *dirs_exist_ok* parameter.
288
289.. function:: rmtree(path, ignore_errors=False, onerror=None)
290
291   .. index:: single: directory; deleting
292
293   Delete an entire directory tree; *path* must point to a directory (but not a
294   symbolic link to a directory).  If *ignore_errors* is true, errors resulting
295   from failed removals will be ignored; if false or omitted, such errors are
296   handled by calling a handler specified by *onerror* or, if that is omitted,
297   they raise an exception.
298
299   .. note::
300
301      On platforms that support the necessary fd-based functions a symlink
302      attack resistant version of :func:`rmtree` is used by default.  On other
303      platforms, the :func:`rmtree` implementation is susceptible to a symlink
304      attack: given proper timing and circumstances, attackers can manipulate
305      symlinks on the filesystem to delete files they wouldn't be able to access
306      otherwise.  Applications can use the :data:`rmtree.avoids_symlink_attacks`
307      function attribute to determine which case applies.
308
309   If *onerror* is provided, it must be a callable that accepts three
310   parameters: *function*, *path*, and *excinfo*.
311
312   The first parameter, *function*, is the function which raised the exception;
313   it depends on the platform and implementation.  The second parameter,
314   *path*, will be the path name passed to *function*.  The third parameter,
315   *excinfo*, will be the exception information returned by
316   :func:`sys.exc_info`.  Exceptions raised by *onerror* will not be caught.
317
318   .. audit-event:: shutil.rmtree path shutil.rmtree
319
320   .. versionchanged:: 3.3
321      Added a symlink attack resistant version that is used automatically
322      if platform supports fd-based functions.
323
324   .. versionchanged:: 3.8
325      On Windows, will no longer delete the contents of a directory junction
326      before removing the junction.
327
328   .. attribute:: rmtree.avoids_symlink_attacks
329
330      Indicates whether the current platform and implementation provides a
331      symlink attack resistant version of :func:`rmtree`.  Currently this is
332      only true for platforms supporting fd-based directory access functions.
333
334      .. versionadded:: 3.3
335
336
337.. function:: move(src, dst, copy_function=copy2)
338
339   Recursively move a file or directory (*src*) to another location (*dst*)
340   and return the destination.
341
342   If the destination is an existing directory, then *src* is moved inside that
343   directory. If the destination already exists but is not a directory, it may
344   be overwritten depending on :func:`os.rename` semantics.
345
346   If the destination is on the current filesystem, then :func:`os.rename` is
347   used. Otherwise, *src* is copied to *dst* using *copy_function* and then
348   removed.  In case of symlinks, a new symlink pointing to the target of *src*
349   will be created in or as *dst* and *src* will be removed.
350
351   If *copy_function* is given, it must be a callable that takes two arguments
352   *src* and *dst*, and will be used to copy *src* to *dst* if
353   :func:`os.rename` cannot be used.  If the source is a directory,
354   :func:`copytree` is called, passing it the :func:`copy_function`. The
355   default *copy_function* is :func:`copy2`.  Using :func:`~shutil.copy` as the
356   *copy_function* allows the move to succeed when it is not possible to also
357   copy the metadata, at the expense of not copying any of the metadata.
358
359   .. audit-event:: shutil.move src,dst shutil.move
360
361   .. versionchanged:: 3.3
362      Added explicit symlink handling for foreign filesystems, thus adapting
363      it to the behavior of GNU's :program:`mv`.
364      Now returns *dst*.
365
366   .. versionchanged:: 3.5
367      Added the *copy_function* keyword argument.
368
369   .. versionchanged:: 3.8
370      Platform-specific fast-copy syscalls may be used internally in order to
371      copy the file more efficiently. See
372      :ref:`shutil-platform-dependent-efficient-copy-operations` section.
373
374.. function:: disk_usage(path)
375
376   Return disk usage statistics about the given path as a :term:`named tuple`
377   with the attributes *total*, *used* and *free*, which are the amount of
378   total, used and free space, in bytes. *path* may be a file or a
379   directory.
380
381   .. versionadded:: 3.3
382
383   .. versionchanged:: 3.8
384     On Windows, *path* can now be a file or directory.
385
386   .. availability:: Unix, Windows.
387
388.. function:: chown(path, user=None, group=None)
389
390   Change owner *user* and/or *group* of the given *path*.
391
392   *user* can be a system user name or a uid; the same applies to *group*. At
393   least one argument is required.
394
395   See also :func:`os.chown`, the underlying function.
396
397   .. audit-event:: shutil.chown path,user,group shutil.chown
398
399   .. availability:: Unix.
400
401   .. versionadded:: 3.3
402
403
404.. function:: which(cmd, mode=os.F_OK | os.X_OK, path=None)
405
406   Return the path to an executable which would be run if the given *cmd* was
407   called.  If no *cmd* would be called, return ``None``.
408
409   *mode* is a permission mask passed to :func:`os.access`, by default
410   determining if the file exists and executable.
411
412   When no *path* is specified, the results of :func:`os.environ` are used,
413   returning either the "PATH" value or a fallback of :attr:`os.defpath`.
414
415   On Windows, the current directory is always prepended to the *path* whether
416   or not you use the default or provide your own, which is the behavior the
417   command shell uses when finding executables.  Additionally, when finding the
418   *cmd* in the *path*, the ``PATHEXT`` environment variable is checked.  For
419   example, if you call ``shutil.which("python")``, :func:`which` will search
420   ``PATHEXT`` to know that it should look for ``python.exe`` within the *path*
421   directories.  For example, on Windows::
422
423      >>> shutil.which("python")
424      'C:\\Python33\\python.EXE'
425
426   .. versionadded:: 3.3
427
428   .. versionchanged:: 3.8
429      The :class:`bytes` type is now accepted.  If *cmd* type is
430      :class:`bytes`, the result type is also :class:`bytes`.
431
432.. exception:: Error
433
434   This exception collects exceptions that are raised during a multi-file
435   operation. For :func:`copytree`, the exception argument is a list of 3-tuples
436   (*srcname*, *dstname*, *exception*).
437
438.. _shutil-platform-dependent-efficient-copy-operations:
439
440Platform-dependent efficient copy operations
441~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
442
443Starting from Python 3.8, all functions involving a file copy
444(:func:`copyfile`, :func:`~shutil.copy`, :func:`copy2`,
445:func:`copytree`, and :func:`move`) may use
446platform-specific "fast-copy" syscalls in order to copy the file more
447efficiently (see :issue:`33671`).
448"fast-copy" means that the copying operation occurs within the kernel, avoiding
449the use of userspace buffers in Python as in "``outfd.write(infd.read())``".
450
451On macOS `fcopyfile`_ is used to copy the file content (not metadata).
452
453On Linux :func:`os.sendfile` is used.
454
455On Windows :func:`shutil.copyfile` uses a bigger default buffer size (1 MiB
456instead of 64 KiB) and a :func:`memoryview`-based variant of
457:func:`shutil.copyfileobj` is used.
458
459If the fast-copy operation fails and no data was written in the destination
460file then shutil will silently fallback on using less efficient
461:func:`copyfileobj` function internally.
462
463.. versionchanged:: 3.8
464
465.. _shutil-copytree-example:
466
467copytree example
468~~~~~~~~~~~~~~~~
469
470This example is the implementation of the :func:`copytree` function, described
471above, with the docstring omitted.  It demonstrates many of the other functions
472provided by this module. ::
473
474   def copytree(src, dst, symlinks=False):
475       names = os.listdir(src)
476       os.makedirs(dst)
477       errors = []
478       for name in names:
479           srcname = os.path.join(src, name)
480           dstname = os.path.join(dst, name)
481           try:
482               if symlinks and os.path.islink(srcname):
483                   linkto = os.readlink(srcname)
484                   os.symlink(linkto, dstname)
485               elif os.path.isdir(srcname):
486                   copytree(srcname, dstname, symlinks)
487               else:
488                   copy2(srcname, dstname)
489               # XXX What about devices, sockets etc.?
490           except OSError as why:
491               errors.append((srcname, dstname, str(why)))
492           # catch the Error from the recursive copytree so that we can
493           # continue with other files
494           except Error as err:
495               errors.extend(err.args[0])
496       try:
497           copystat(src, dst)
498       except OSError as why:
499           # can't copy file access times on Windows
500           if why.winerror is None:
501               errors.extend((src, dst, str(why)))
502       if errors:
503           raise Error(errors)
504
505Another example that uses the :func:`ignore_patterns` helper::
506
507   from shutil import copytree, ignore_patterns
508
509   copytree(source, destination, ignore=ignore_patterns('*.pyc', 'tmp*'))
510
511This will copy everything except ``.pyc`` files and files or directories whose
512name starts with ``tmp``.
513
514Another example that uses the *ignore* argument to add a logging call::
515
516   from shutil import copytree
517   import logging
518
519   def _logpath(path, names):
520       logging.info('Working in %s', path)
521       return []   # nothing will be ignored
522
523   copytree(source, destination, ignore=_logpath)
524
525
526.. _shutil-rmtree-example:
527
528rmtree example
529~~~~~~~~~~~~~~
530
531This example shows how to remove a directory tree on Windows where some
532of the files have their read-only bit set. It uses the onerror callback
533to clear the readonly bit and reattempt the remove. Any subsequent failure
534will propagate. ::
535
536    import os, stat
537    import shutil
538
539    def remove_readonly(func, path, _):
540        "Clear the readonly bit and reattempt the removal"
541        os.chmod(path, stat.S_IWRITE)
542        func(path)
543
544    shutil.rmtree(directory, onerror=remove_readonly)
545
546.. _archiving-operations:
547
548Archiving operations
549--------------------
550
551.. versionadded:: 3.2
552
553.. versionchanged:: 3.5
554    Added support for the *xztar* format.
555
556
557High-level utilities to create and read compressed and archived files are also
558provided.  They rely on the :mod:`zipfile` and :mod:`tarfile` modules.
559
560.. function:: make_archive(base_name, format, [root_dir, [base_dir, [verbose, [dry_run, [owner, [group, [logger]]]]]]])
561
562   Create an archive file (such as zip or tar) and return its name.
563
564   *base_name* is the name of the file to create, including the path, minus
565   any format-specific extension. *format* is the archive format: one of
566   "zip" (if the :mod:`zlib` module is available), "tar", "gztar" (if the
567   :mod:`zlib` module is available), "bztar" (if the :mod:`bz2` module is
568   available), or "xztar" (if the :mod:`lzma` module is available).
569
570   *root_dir* is a directory that will be the root directory of the
571   archive, all paths in the archive will be relative to it; for example,
572   we typically chdir into *root_dir* before creating the archive.
573
574   *base_dir* is the directory where we start archiving from;
575   i.e. *base_dir* will be the common prefix of all files and
576   directories in the archive.  *base_dir* must be given relative
577   to *root_dir*.  See :ref:`shutil-archiving-example-with-basedir` for how to
578   use *base_dir* and *root_dir* together.
579
580   *root_dir* and *base_dir* both default to the current directory.
581
582   If *dry_run* is true, no archive is created, but the operations that would be
583   executed are logged to *logger*.
584
585   *owner* and *group* are used when creating a tar archive. By default,
586   uses the current owner and group.
587
588   *logger* must be an object compatible with :pep:`282`, usually an instance of
589   :class:`logging.Logger`.
590
591   The *verbose* argument is unused and deprecated.
592
593   .. audit-event:: shutil.make_archive base_name,format,root_dir,base_dir shutil.make_archive
594
595   .. note::
596
597      This function is not thread-safe.
598
599   .. versionchanged:: 3.8
600      The modern pax (POSIX.1-2001) format is now used instead of
601      the legacy GNU format for archives created with ``format="tar"``.
602
603
604.. function:: get_archive_formats()
605
606   Return a list of supported formats for archiving.
607   Each element of the returned sequence is a tuple ``(name, description)``.
608
609   By default :mod:`shutil` provides these formats:
610
611   - *zip*: ZIP file (if the :mod:`zlib` module is available).
612   - *tar*: Uncompressed tar file. Uses POSIX.1-2001 pax format for new archives.
613   - *gztar*: gzip'ed tar-file (if the :mod:`zlib` module is available).
614   - *bztar*: bzip2'ed tar-file (if the :mod:`bz2` module is available).
615   - *xztar*: xz'ed tar-file (if the :mod:`lzma` module is available).
616
617   You can register new formats or provide your own archiver for any existing
618   formats, by using :func:`register_archive_format`.
619
620
621.. function:: register_archive_format(name, function, [extra_args, [description]])
622
623   Register an archiver for the format *name*.
624
625   *function* is the callable that will be used to unpack archives. The callable
626   will receive the *base_name* of the file to create, followed by the
627   *base_dir* (which defaults to :data:`os.curdir`) to start archiving from.
628   Further arguments are passed as keyword arguments: *owner*, *group*,
629   *dry_run* and *logger* (as passed in :func:`make_archive`).
630
631   If given, *extra_args* is a sequence of ``(name, value)`` pairs that will be
632   used as extra keywords arguments when the archiver callable is used.
633
634   *description* is used by :func:`get_archive_formats` which returns the
635   list of archivers.  Defaults to an empty string.
636
637
638.. function:: unregister_archive_format(name)
639
640   Remove the archive format *name* from the list of supported formats.
641
642
643.. function:: unpack_archive(filename[, extract_dir[, format]])
644
645   Unpack an archive. *filename* is the full path of the archive.
646
647   *extract_dir* is the name of the target directory where the archive is
648   unpacked. If not provided, the current working directory is used.
649
650   *format* is the archive format: one of "zip", "tar", "gztar", "bztar", or
651   "xztar".  Or any other format registered with
652   :func:`register_unpack_format`.  If not provided, :func:`unpack_archive`
653   will use the archive file name extension and see if an unpacker was
654   registered for that extension.  In case none is found,
655   a :exc:`ValueError` is raised.
656
657   .. audit-event:: shutil.unpack_archive filename,extract_dir,format shutil.unpack_archive
658
659   .. versionchanged:: 3.7
660      Accepts a :term:`path-like object` for *filename* and *extract_dir*.
661
662
663.. function:: register_unpack_format(name, extensions, function[, extra_args[, description]])
664
665   Registers an unpack format. *name* is the name of the format and
666   *extensions* is a list of extensions corresponding to the format, like
667   ``.zip`` for Zip files.
668
669   *function* is the callable that will be used to unpack archives. The
670   callable will receive the path of the archive, followed by the directory
671   the archive must be extracted to.
672
673   When provided, *extra_args* is a sequence of ``(name, value)`` tuples that
674   will be passed as keywords arguments to the callable.
675
676   *description* can be provided to describe the format, and will be returned
677   by the :func:`get_unpack_formats` function.
678
679
680.. function:: unregister_unpack_format(name)
681
682   Unregister an unpack format. *name* is the name of the format.
683
684
685.. function:: get_unpack_formats()
686
687   Return a list of all registered formats for unpacking.
688   Each element of the returned sequence is a tuple
689   ``(name, extensions, description)``.
690
691   By default :mod:`shutil` provides these formats:
692
693   - *zip*: ZIP file (unpacking compressed files works only if the corresponding
694     module is available).
695   - *tar*: uncompressed tar file.
696   - *gztar*: gzip'ed tar-file (if the :mod:`zlib` module is available).
697   - *bztar*: bzip2'ed tar-file (if the :mod:`bz2` module is available).
698   - *xztar*: xz'ed tar-file (if the :mod:`lzma` module is available).
699
700   You can register new formats or provide your own unpacker for any existing
701   formats, by using :func:`register_unpack_format`.
702
703
704.. _shutil-archiving-example:
705
706Archiving example
707~~~~~~~~~~~~~~~~~
708
709In this example, we create a gzip'ed tar-file archive containing all files
710found in the :file:`.ssh` directory of the user::
711
712    >>> from shutil import make_archive
713    >>> import os
714    >>> archive_name = os.path.expanduser(os.path.join('~', 'myarchive'))
715    >>> root_dir = os.path.expanduser(os.path.join('~', '.ssh'))
716    >>> make_archive(archive_name, 'gztar', root_dir)
717    '/Users/tarek/myarchive.tar.gz'
718
719The resulting archive contains:
720
721.. code-block:: shell-session
722
723    $ tar -tzvf /Users/tarek/myarchive.tar.gz
724    drwx------ tarek/staff       0 2010-02-01 16:23:40 ./
725    -rw-r--r-- tarek/staff     609 2008-06-09 13:26:54 ./authorized_keys
726    -rwxr-xr-x tarek/staff      65 2008-06-09 13:26:54 ./config
727    -rwx------ tarek/staff     668 2008-06-09 13:26:54 ./id_dsa
728    -rwxr-xr-x tarek/staff     609 2008-06-09 13:26:54 ./id_dsa.pub
729    -rw------- tarek/staff    1675 2008-06-09 13:26:54 ./id_rsa
730    -rw-r--r-- tarek/staff     397 2008-06-09 13:26:54 ./id_rsa.pub
731    -rw-r--r-- tarek/staff   37192 2010-02-06 18:23:10 ./known_hosts
732
733
734.. _shutil-archiving-example-with-basedir:
735
736Archiving example with *base_dir*
737~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
738
739In this example, similar to the `one above <shutil-archiving-example_>`_,
740we show how to use :func:`make_archive`, but this time with the usage of
741*base_dir*.  We now have the following directory structure:
742
743.. code-block:: shell-session
744
745    $ tree tmp
746    tmp
747    └── root
748        └── structure
749            ├── content
750                └── please_add.txt
751            └── do_not_add.txt
752
753In the final archive, :file:`please_add.txt` should be included, but
754:file:`do_not_add.txt` should not.  Therefore we use the following::
755
756    >>> from shutil import make_archive
757    >>> import os
758    >>> archive_name = os.path.expanduser(os.path.join('~', 'myarchive'))
759    >>> make_archive(
760    ...     archive_name,
761    ...     'tar',
762    ...     root_dir='tmp/root',
763    ...     base_dir='structure/content',
764    ... )
765    '/Users/tarek/my_archive.tar'
766
767Listing the files in the resulting archive gives us:
768
769.. code-block:: shell-session
770
771    $ python -m tarfile -l /Users/tarek/myarchive.tar
772    structure/content/
773    structure/content/please_add.txt
774
775
776Querying the size of the output terminal
777----------------------------------------
778
779.. function:: get_terminal_size(fallback=(columns, lines))
780
781   Get the size of the terminal window.
782
783   For each of the two dimensions, the environment variable, ``COLUMNS``
784   and ``LINES`` respectively, is checked. If the variable is defined and
785   the value is a positive integer, it is used.
786
787   When ``COLUMNS`` or ``LINES`` is not defined, which is the common case,
788   the terminal connected to :data:`sys.__stdout__` is queried
789   by invoking :func:`os.get_terminal_size`.
790
791   If the terminal size cannot be successfully queried, either because
792   the system doesn't support querying, or because we are not
793   connected to a terminal, the value given in ``fallback`` parameter
794   is used. ``fallback`` defaults to ``(80, 24)`` which is the default
795   size used by many terminal emulators.
796
797   The value returned is a named tuple of type :class:`os.terminal_size`.
798
799   See also: The Single UNIX Specification, Version 2,
800   `Other Environment Variables`_.
801
802   .. versionadded:: 3.3
803
804.. _`fcopyfile`:
805   http://www.manpagez.com/man/3/copyfile/
806
807.. _`Other Environment Variables`:
808   http://pubs.opengroup.org/onlinepubs/7908799/xbd/envvar.html#tag_002_003
809