"shutil" — 高階檔案操作
***********************

**原始碼：**Lib/shutil.py

======================================================================

The "shutil" module offers a number of high-level operations on files
and collections of files.  In particular, functions are provided
which support file copying and removal. For operations on individual
files, see also the "os" module.

警告:

  Even the higher-level file copying functions ("shutil.copy()",
  "shutil.copy2()") cannot copy all file metadata.On POSIX platforms,
  this means that file owner and group are lost as well as ACLs.  On
  Mac OS, the resource fork and other metadata are not used. This
  means that resources will be lost and file type and creator codes
  will not be correct. On Windows, file owners, ACLs and alternate
  data streams are not copied.


Directory and files operations
==============================

shutil.copyfileobj(fsrc, fdst[, length])

   Copy the contents of the *file-like object* *fsrc* to the file-like
   object *fdst*. The integer *length*, if given, is the buffer size.
   In particular, a negative *length* value means to copy the data
   without looping over the source data in chunks; by default the data
   is read in chunks to avoid uncontrolled memory consumption. Note
   that if the current file position of the *fsrc* object is not 0,
   only the contents from the current file position to the end of the
   file will be copied.

shutil.copyfile(src, dst, *, follow_symlinks=True)

   Copy the contents (no metadata) of the file named *src* to a file
   named *dst* and return *dst* in the most efficient way possible.
   *src* and *dst* are *path-like objects* or path names given as
   strings.

   *dst* must be the complete target file name; look at "copy()" for a
   copy that accepts a target directory path.  If *src* and *dst*
   specify the same file, "SameFileError" is raised.

   The destination location must be writable; otherwise, an "OSError"
   exception will be raised. If *dst* already exists, it will be
   replaced. Special files such as character or block devices and
   pipes cannot be copied with this function.

   If *follow_symlinks* is false and *src* is a symbolic link, a new
   symbolic link will be created instead of copying the file *src*
   points to.

   引發一個附帶引數 "src"、"dst" 的稽核事件 "shutil.copyfile"。

   在 3.3 版的變更: "IOError" used to be raised instead of "OSError".
   Added *follow_symlinks* argument. Now returns *dst*.

   在 3.4 版的變更: Raise "SameFileError" instead of "Error".  Since
   the former is a subclass of the latter, this change is backward
   compatible.

   在 3.8 版的變更: Platform-specific fast-copy syscalls may be used
   internally in order to copy the file more efficiently. See
   Platform-dependent efficient copy operations section.

exception shutil.SpecialFileError

   This exception is raised when "copyfile()" or "copytree()" attempt
   to copy a named pipe.

   在 2.7 版被加入.

exception shutil.SameFileError

   This exception is raised if source and destination in "copyfile()"
   are the same file.

   在 3.4 版被加入.

shutil.copymode(src, dst, *, follow_symlinks=True)

   Copy the permission bits from *src* to *dst*.  The file contents,
   owner, and group are unaffected.  *src* and *dst* are *path-like
   objects* or path names given as strings. If *follow_symlinks* is
   false, and both *src* and *dst* are symbolic links, "copymode()"
   will attempt to modify the mode of *dst* itself (rather than the
   file it points to).  This functionality is not available on every
   platform; please see "copystat()" for more information.  If
   "copymode()" cannot modify symbolic links on the local platform,
   and it is asked to do so, it will do nothing and return.

   引發一個附帶引數 "src"、"dst" 的稽核事件 "shutil.copymode"。

   在 3.3 版的變更: 新增 *follow_symlinks* 引數。

shutil.copystat(src, dst, *, follow_symlinks=True)

   Copy the permission bits, last access time, last modification time,
   and flags from *src* to *dst*.  On Linux, "copystat()" also copies
   the "extended attributes" where possible.  The file contents,
   owner, and group are unaffected.  *src* and *dst* are *path-like
   objects* or path names given as strings.

   If *follow_symlinks* is false, and *src* and *dst* both refer to
   symbolic links, "copystat()" will operate on the symbolic links
   themselves rather than the files the symbolic links refer
   to—reading the information from the *src* symbolic link, and
   writing the information to the *dst* symbolic link.

   備註:

     Not all platforms provide the ability to examine and modify
     symbolic links.  Python itself can tell you what functionality is
     locally available.

     * If "os.chmod in os.supports_follow_symlinks" is "True",
       "copystat()" can modify the permission bits of a symbolic link.

     * If "os.utime in os.supports_follow_symlinks" is "True",
       "copystat()" can modify the last access and modification times
       of a symbolic link.

     * If "os.chflags in os.supports_follow_symlinks" is "True",
       "copystat()" can modify the flags of a symbolic link.
       ("os.chflags" is not available on all platforms.)

     On platforms where some or all of this functionality is
     unavailable, when asked to modify a symbolic link, "copystat()"
     will copy everything it can. "copystat()" never returns failure.
     更多資訊請見 "os.supports_follow_symlinks"。

   引發一個附帶引數 "src"、"dst" 的稽核事件 "shutil.copystat"。

   在 3.3 版的變更: Added *follow_symlinks* argument and support for
   Linux extended attributes.

shutil.copy(src, dst, *, follow_symlinks=True)

   Copies the file *src* to the file or directory *dst*.  *src* and
   *dst* should be *path-like objects* or strings.  If *dst* specifies
   a directory, the file will be copied into *dst* using the base
   filename from *src*. If *dst* specifies a file that already exists,
   it will be replaced. Returns the path to the newly created file.

   If *follow_symlinks* is false, and *src* is a symbolic link, *dst*
   will be created as a symbolic link.  If *follow_symlinks* is true
   and *src* is a symbolic link, *dst* will be a copy of the file
   *src* refers to.

   "copy()" copies the file data and the file's permission mode (see
   "os.chmod()").  Other metadata, like the file's creation and
   modification times, is not preserved. To preserve all file metadata
   from the original, use "copy2()" instead.

   引發一個附帶引數 "src"、"dst" 的稽核事件 "shutil.copyfile"。

   引發一個附帶引數 "src"、"dst" 的稽核事件 "shutil.copymode"。

   在 3.3 版的變更: Added *follow_symlinks* argument. Now returns path
   to the newly created file.

   在 3.8 版的變更: Platform-specific fast-copy syscalls may be used
   internally in order to copy the file more efficiently. See
   Platform-dependent efficient copy operations section.

shutil.copy2(src, dst, *, follow_symlinks=True)

   Identical to "copy()" except that "copy2()" also attempts to
   preserve file metadata.

   When *follow_symlinks* is false, and *src* is a symbolic link,
   "copy2()" attempts to copy all metadata from the *src* symbolic
   link to the newly created *dst* symbolic link. However, this
   functionality is not available on all platforms. On platforms where
   some or all of this functionality is unavailable, "copy2()" will
   preserve all the metadata it can; "copy2()" never raises an
   exception because it cannot preserve file metadata.

   "copy2()" uses "copystat()" to copy the file metadata. Please see
   "copystat()" for more information about platform support for
   modifying symbolic link metadata.

   引發一個附帶引數 "src"、"dst" 的稽核事件 "shutil.copyfile"。

   引發一個附帶引數 "src"、"dst" 的稽核事件 "shutil.copystat"。

   在 3.3 版的變更: Added *follow_symlinks* argument, try to copy
   extended file system attributes too (currently Linux only). Now
   returns path to the newly created file.

   在 3.8 版的變更: Platform-specific fast-copy syscalls may be used
   internally in order to copy the file more efficiently. See
   Platform-dependent efficient copy operations section.

shutil.ignore_patterns(*patterns)

   This factory function creates a function that can be used as a
   callable for "copytree()"'s *ignore* argument, ignoring files and
   directories that match one of the glob-style *patterns* provided.
   See the example below.

shutil.copytree(src, dst, symlinks=False, ignore=None, copy_function=copy2, ignore_dangling_symlinks=False, dirs_exist_ok=False)

   Recursively copy an entire directory tree rooted at *src* to a
   directory named *dst* and return the destination directory.  All
   intermediate directories needed to contain *dst* will also be
   created by default.

   Permissions and times of directories are copied with "copystat()",
   individual files are copied using "copy2()".

   If *symlinks* is true, symbolic links in the source tree are
   represented as symbolic links in the new tree and the metadata of
   the original links will be copied as far as the platform allows; if
   false or omitted, the contents and metadata of the linked files are
   copied to the new tree.

   When *symlinks* is false, if the file pointed to by the symlink
   doesn't exist, an exception will be added in the list of errors
   raised in an "Error" exception at the end of the copy process. You
   can set the optional *ignore_dangling_symlinks* flag to true if you
   want to silence this exception. Notice that this option has no
   effect on platforms that don't support "os.symlink()".

   If *ignore* is given, it must be a callable that will receive as
   its arguments the directory being visited by "copytree()", and a
   list of its contents, as returned by "os.listdir()".  Since
   "copytree()" is called recursively, the *ignore* callable will be
   called once for each directory that is copied.  The callable must
   return a sequence of directory and file names relative to the
   current directory (i.e. a subset of the items in its second
   argument); these names will then be ignored in the copy process.
   "ignore_patterns()" can be used to create such a callable that
   ignores names based on glob-style patterns.

   If exception(s) occur, an "Error" is raised with a list of reasons.

   If *copy_function* is given, it must be a callable that will be
   used to copy each file. It will be called with the source path and
   the destination path as arguments. By default, "copy2()" is used,
   but any function that supports the same signature (like "copy()")
   can be used.

   If *dirs_exist_ok* is false (the default) and *dst* already exists,
   a "FileExistsError" is raised. If *dirs_exist_ok* is true, the
   copying operation will continue if it encounters existing
   directories, and files within the *dst* tree will be overwritten by
   corresponding files from the *src* tree.

   引發一個附帶引數 "src"、"dst" 的稽核事件 "shutil.copytree"。

   在 3.2 版的變更: Added the *copy_function* argument to be able to
   provide a custom copy function. Added the
   *ignore_dangling_symlinks* argument to silence dangling symlinks
   errors when *symlinks* is false.

   在 3.3 版的變更: Copy metadata when *symlinks* is false. Now
   returns *dst*.

   在 3.8 版的變更: Platform-specific fast-copy syscalls may be used
   internally in order to copy the file more efficiently. See
   Platform-dependent efficient copy operations section.

   在 3.8 版的變更: 新增 *dirs_exist_ok* 參數。

shutil.rmtree(path, ignore_errors=False, onerror=None, *, onexc=None, dir_fd=None)

   Delete an entire directory tree; *path* must point to a directory
   (but not a symbolic link to a directory).  If *ignore_errors* is
   true, errors resulting from failed removals will be ignored; if
   false or omitted, such errors are handled by calling a handler
   specified by *onexc* or *onerror* or, if both are omitted,
   exceptions are propagated to the caller.

   This function can support paths relative to directory descriptors.

   備註:

     On platforms that support the necessary fd-based functions a
     symlink attack resistant version of "rmtree()" is used by
     default.  On other platforms, the "rmtree()" implementation is
     susceptible to a symlink attack: given proper timing and
     circumstances, attackers can manipulate symlinks on the
     filesystem to delete files they wouldn't be able to access
     otherwise.  Applications can use the
     "rmtree.avoids_symlink_attacks" function attribute to determine
     which case applies.

   If *onexc* is provided, it must be a callable that accepts three
   parameters: *function*, *path*, and *excinfo*.

   The first parameter, *function*, is the function which raised the
   exception; it depends on the platform and implementation.  The
   second parameter, *path*, will be the path name passed to
   *function*.  The third parameter, *excinfo*, is the exception that
   was raised. Exceptions raised by *onexc* will not be caught.

   The deprecated *onerror* is similar to *onexc*, except that the
   third parameter it receives is the tuple returned from
   "sys.exc_info()".

   也參考:

     rmtree 範例 for an example of handling the removal of a directory
     tree that contains read-only files.

   引發一個附帶引數 "path"、"dir_fd" 的稽核事件 "shutil.rmtree"。

   在 3.3 版的變更: Added a symlink attack resistant version that is
   used automatically if platform supports fd-based functions.

   在 3.8 版的變更: On Windows, will no longer delete the contents of
   a directory junction before removing the junction.

   在 3.11 版的變更: 新增 *dir_fd* 參數。

   在 3.12 版的變更: 新增 *onexc* 參數並棄用 *onerror*。

   在 3.13 版的變更: "rmtree()" now ignores "FileNotFoundError"
   exceptions for all but the top-level path. Exceptions other than
   "OSError" and subclasses of "OSError" are now always propagated to
   the caller.

   rmtree.avoids_symlink_attacks

      Indicates whether the current platform and implementation
      provides a symlink attack resistant version of "rmtree()".
      Currently this is only true for platforms supporting fd-based
      directory access functions.

      在 3.3 版被加入.

shutil.move(src, dst, copy_function=copy2)

   Recursively move a file or directory (*src*) to another location
   and return the destination.

   If *dst* is an existing directory or a symlink to a directory, then
   *src* is moved inside that directory. The destination path in that
   directory must not already exist.

   If *dst* already exists but is not a directory, it may be
   overwritten depending on "os.rename()" semantics.

   If the destination is on the current filesystem, then "os.rename()"
   is used. Otherwise, *src* is copied to the destination using
   *copy_function* and then removed.  In case of symlinks, a new
   symlink pointing to the target of *src* will be created as the
   destination and *src* will be removed.

   If *copy_function* is given, it must be a callable that takes two
   arguments, *src* and the destination, and will be used to copy
   *src* to the destination if "os.rename()" cannot be used.  If the
   source is a directory, "copytree()" is called, passing it the
   *copy_function*. The default *copy_function* is "copy2()".  Using
   "copy()" as the *copy_function* allows the move to succeed when it
   is not possible to also copy the metadata, at the expense of not
   copying any of the metadata.

   引發一個附帶引數 "src"、"dst" 的稽核事件 "shutil.move"。

   在 3.3 版的變更: Added explicit symlink handling for foreign
   filesystems, thus adapting it to the behavior of GNU's **mv**. Now
   returns *dst*.

   在 3.5 版的變更: 新增 *copy_function* 關鍵字引數。

   在 3.8 版的變更: Platform-specific fast-copy syscalls may be used
   internally in order to copy the file more efficiently. See
   Platform-dependent efficient copy operations section.

   在 3.9 版的變更: Accepts a *path-like object* for both *src* and
   *dst*.

shutil.disk_usage(path)

   Return disk usage statistics about the given path as a *named
   tuple* with the attributes *total*, *used* and *free*, which are
   the amount of total, used and free space, in bytes. *path* may be a
   file or a directory.

   備註:

     On Unix filesystems, *path* must point to a path within a
     **mounted** filesystem partition. On those platforms, CPython
     doesn't attempt to retrieve disk usage information from non-
     mounted filesystems.

   在 3.3 版被加入.

   在 3.8 版的變更: On Windows, *path* can now be a file or directory.

   可用性: Unix, Windows.

shutil.chown(path, user=None, group=None, *, dir_fd=None, follow_symlinks=True)

   Change owner *user* and/or *group* of the given *path*.

   *user* can be a system user name or a uid; the same applies to
   *group*. At least one argument is required.

   See also "os.chown()", the underlying function.

   引發一個附帶引數 "path"、"user"、"group" 的稽核事件 "shutil.chown"
   。

   可用性: Unix.

   在 3.3 版被加入.

   在 3.13 版的變更: 新增 *dir_fd* 和 *follow_symlinks* 參數。

shutil.which(cmd, mode=os.F_OK | os.X_OK, path=None)

   Return the path to an executable which would be run if the given
   *cmd* was called.  If no *cmd* would be called, return "None".

   *mode* is a permission mask passed to "os.access()", by default
   determining if the file exists and is executable.

   *path* is a ""PATH" string" specifying the directories to look in,
   delimited by "os.pathsep". When no *path* is specified, the "PATH"
   environment variable is read from "os.environ", falling back to
   "os.defpath" if it is not set.

   If *cmd* contains a directory component, "which()" only checks the
   specified path directly and does not search the directories listed
   in *path* or in the system's "PATH" environment variable.

   On Windows, the current directory is prepended to the *path* if
   *mode* does not include "os.X_OK". When the *mode* does include
   "os.X_OK", the Windows API "NeedCurrentDirectoryForExePathW" will
   be consulted to determine if the current directory should be
   prepended to *path*. To avoid consulting the current working
   directory for executables: set the environment variable
   "NoDefaultCurrentDirectoryInExePath".

   Also on Windows, the "PATHEXT" environment variable is used to
   resolve commands that may not already include an extension. For
   example, if you call "shutil.which("python")", "which()" will
   search "PATHEXT" to know that it should look for "python.exe"
   within the *path* directories. For example, on Windows:

      >>> shutil.which("python")
      'C:\\Python33\\python.EXE'

   This is also applied when *cmd* is a path that contains a directory
   component:

      >>> shutil.which("C:\\Python33\\python")
      'C:\\Python33\\python.EXE'

   在 3.3 版被加入.

   在 3.8 版的變更: The "bytes" type is now accepted.  If *cmd* type
   is "bytes", the result type is also "bytes".

   在 3.12 版的變更: On Windows, the current directory is no longer
   prepended to the search path if *mode* includes "os.X_OK" and
   WinAPI "NeedCurrentDirectoryForExePathW(cmd)" is false, else the
   current directory is prepended even if it is already in the search
   path; "PATHEXT" is used now even when *cmd* includes a directory
   component or ends with an extension that is in "PATHEXT"; and
   filenames that have no extension can now be found.

exception shutil.Error

   This exception collects exceptions that are raised during a multi-
   file operation. For "copytree()", the exception argument is a list
   of 3-tuples (*srcname*, *dstname*, *exception*).


Platform-dependent efficient copy operations
--------------------------------------------

Starting from Python 3.8, all functions involving a file copy
("copyfile()", "copy()", "copy2()", "copytree()", and "move()") may
use platform-specific "fast-copy" syscalls in order to copy the file
more efficiently (see bpo-33671). "fast-copy" means that the copying
operation occurs within the kernel, avoiding the use of userspace
buffers in Python as in ""outfd.write(infd.read())"".

On macOS fcopyfile is used to copy the file content (not metadata).

On Linux "os.sendfile()" is used.

On Windows "shutil.copyfile()" uses a bigger default buffer size (1
MiB instead of 64 KiB) and a "memoryview()"-based variant of
"shutil.copyfileobj()" is used.

If the fast-copy operation fails and no data was written in the
destination file then shutil will silently fallback on using less
efficient "copyfileobj()" function internally.

在 3.8 版的變更.


copytree 範例
-------------

An example that uses the "ignore_patterns()" helper:

   from shutil import copytree, ignore_patterns

   copytree(source, destination, ignore=ignore_patterns('*.pyc', 'tmp*'))

This will copy everything except ".pyc" files and files or directories
whose name starts with "tmp".

Another example that uses the *ignore* argument to add a logging call:

   from shutil import copytree
   import logging

   def _logpath(path, names):
       logging.info('Working in %s', path)
       return []   # nothing will be ignored

   copytree(source, destination, ignore=_logpath)


rmtree 範例
-----------

This example shows how to remove a directory tree on Windows where
some of the files have their read-only bit set. It uses the onexc
callback to clear the readonly bit and reattempt the remove. Any
subsequent failure will propagate.

   import os, stat
   import shutil

   def remove_readonly(func, path, _):
       "Clear the readonly bit and reattempt the removal"
       os.chmod(path, stat.S_IWRITE)
       func(path)

   shutil.rmtree(directory, onexc=remove_readonly)


Archiving operations
====================

在 3.2 版被加入.

在 3.5 版的變更: 新增 *xztar* 格式的支援。

High-level utilities to create and read compressed and archived files
are also provided.  They rely on the "zipfile" and "tarfile" modules.

shutil.make_archive(base_name, format[, root_dir[, base_dir[, verbose[, dry_run[, owner[, group[, logger]]]]]]])

   Create an archive file (such as zip or tar) and return its name.

   *base_name* is the name of the file to create, including the path,
   minus any format-specific extension.

   *format* is the archive format: one of "zip" (if the "zlib" module
   is available), "tar", "gztar" (if the "zlib" module is available),
   "bztar" (if the "bz2" module is available), or "xztar" (if the
   "lzma" module is available).

   *root_dir* is a directory that will be the root directory of the
   archive, all paths in the archive will be relative to it; for
   example, we typically chdir into *root_dir* before creating the
   archive.

   *base_dir* is the directory where we start archiving from; i.e.
   *base_dir* will be the common prefix of all files and directories
   in the archive.  *base_dir* must be given relative to *root_dir*.
   See Archiving example with base_dir for how to use *base_dir* and
   *root_dir* together.

   *root_dir* and *base_dir* both default to the current directory.

   If *dry_run* is true, no archive is created, but the operations
   that would be executed are logged to *logger*.

   *owner* and *group* are used when creating a tar archive. By
   default, uses the current owner and group.

   *logger* must be an object compatible with **PEP 282**, usually an
   instance of "logging.Logger".

   The *verbose* argument is unused and deprecated.

   引發一個附帶引數 "base_name"、"format"、"root_dir"、"base_dir" 的稽
   核事件 "shutil.make_archive"。

   備註:

     This function is not thread-safe when custom archivers registered
     with "register_archive_format()" do not support the *root_dir*
     argument.  In this case it temporarily changes the current
     working directory of the process to *root_dir* to perform
     archiving.

   在 3.8 版的變更: The modern pax (POSIX.1-2001) format is now used
   instead of the legacy GNU format for archives created with
   "format="tar"".

   在 3.10.6 版的變更: This function is now made thread-safe during
   creation of standard ".zip" and tar archives.

shutil.get_archive_formats()

   Return a list of supported formats for archiving. Each element of
   the returned sequence is a tuple "(name, description)".

   By default "shutil" provides these formats:

   * *zip*: ZIP file (if the "zlib" module is available).

   * *tar*: Uncompressed tar file. Uses POSIX.1-2001 pax format for
     new archives.

   * *gztar*: gzip'ed tar-file (if the "zlib" module is available).

   * *bztar*: bzip2'ed tar-file (if the "bz2" module is available).

   * *xztar*: xz'ed tar-file (if the "lzma" module is available).

   You can register new formats or provide your own archiver for any
   existing formats, by using "register_archive_format()".

shutil.register_archive_format(name, function[, extra_args[, description]])

   Register an archiver for the format *name*.

   *function* is the callable that will be used to unpack archives.
   The callable will receive the *base_name* of the file to create,
   followed by the *base_dir* (which defaults to "os.curdir") to start
   archiving from. Further arguments are passed as keyword arguments:
   *owner*, *group*, *dry_run* and *logger* (as passed in
   "make_archive()").

   If *function* has the custom attribute "function.supports_root_dir"
   set to "True", the *root_dir* argument is passed as a keyword
   argument. Otherwise the current working directory of the process is
   temporarily changed to *root_dir* before calling *function*. In
   this case "make_archive()" is not thread-safe.

   If given, *extra_args* is a sequence of "(name, value)" pairs that
   will be used as extra keywords arguments when the archiver callable
   is used.

   *description* is used by "get_archive_formats()" which returns the
   list of archivers.  Defaults to an empty string.

   在 3.12 版的變更: Added support for functions supporting the
   *root_dir* argument.

shutil.unregister_archive_format(name)

   Remove the archive format *name* from the list of supported
   formats.

shutil.unpack_archive(filename[, extract_dir[, format[, filter]]])

   Unpack an archive. *filename* is the full path of the archive.

   *extract_dir* is the name of the target directory where the archive
   is unpacked. If not provided, the current working directory is
   used.

   *format* is the archive format: one of "zip", "tar", "gztar",
   "bztar", or "xztar".  Or any other format registered with
   "register_unpack_format()".  If not provided, "unpack_archive()"
   will use the archive file name extension and see if an unpacker was
   registered for that extension.  In case none is found, a
   "ValueError" is raised.

   The keyword-only *filter* argument is passed to the underlying
   unpacking function. For zip files, *filter* is not accepted. For
   tar files, it is recommended to set it to "'data'", unless using
   features specific to tar and UNIX-like filesystems. (See Extraction
   filters for details.) The "'data'" filter will become the default
   for tar files in Python 3.14.

   引發一個附帶引數 "filename"、"extract_dir"、"format" 的稽核事件
   "shutil.unpack_archive"。

   警告:

     Never extract archives from untrusted sources without prior
     inspection. It is possible that files are created outside of the
     path specified in the *extract_dir* argument, e.g. members that
     have absolute filenames starting with "/" or filenames with two
     dots "..".

   在 3.7 版的變更: Accepts a *path-like object* for *filename* and
   *extract_dir*.

   在 3.12 版的變更: 新增 *filter* 引數。

shutil.register_unpack_format(name, extensions, function[, extra_args[, description]])

   Registers an unpack format. *name* is the name of the format and
   *extensions* is a list of extensions corresponding to the format,
   like ".zip" for Zip files.

   *function* is the callable that will be used to unpack archives.
   The callable will receive:

   * the path of the archive, as a positional argument;

   * the directory the archive must be extracted to, as a positional
     argument;

   * possibly a *filter* keyword argument, if it was given to
     "unpack_archive()";

   * additional keyword arguments, specified by *extra_args* as a
     sequence of "(name, value)" tuples.

   *description* can be provided to describe the format, and will be
   returned by the "get_unpack_formats()" function.

shutil.unregister_unpack_format(name)

   Unregister an unpack format. *name* is the name of the format.

shutil.get_unpack_formats()

   Return a list of all registered formats for unpacking. Each element
   of the returned sequence is a tuple "(name, extensions,
   description)".

   By default "shutil" provides these formats:

   * *zip*: ZIP file (unpacking compressed files works only if the
     corresponding module is available).

   * *tar*: uncompressed tar file.

   * *gztar*: gzip'ed tar-file (if the "zlib" module is available).

   * *bztar*: bzip2'ed tar-file (if the "bz2" module is available).

   * *xztar*: xz'ed tar-file (if the "lzma" module is available).

   You can register new formats or provide your own unpacker for any
   existing formats, by using "register_unpack_format()".


Archiving example
-----------------

In this example, we create a gzip'ed tar-file archive containing all
files found in the ".ssh" directory of the user:

   >>> from shutil import make_archive
   >>> import os
   >>> archive_name = os.path.expanduser(os.path.join('~', 'myarchive'))
   >>> root_dir = os.path.expanduser(os.path.join('~', '.ssh'))
   >>> make_archive(archive_name, 'gztar', root_dir)
   '/Users/tarek/myarchive.tar.gz'

The resulting archive contains:

   $ tar -tzvf /Users/tarek/myarchive.tar.gz
   drwx------ tarek/staff       0 2010-02-01 16:23:40 ./
   -rw-r--r-- tarek/staff     609 2008-06-09 13:26:54 ./authorized_keys
   -rwxr-xr-x tarek/staff      65 2008-06-09 13:26:54 ./config
   -rwx------ tarek/staff     668 2008-06-09 13:26:54 ./id_dsa
   -rwxr-xr-x tarek/staff     609 2008-06-09 13:26:54 ./id_dsa.pub
   -rw------- tarek/staff    1675 2008-06-09 13:26:54 ./id_rsa
   -rw-r--r-- tarek/staff     397 2008-06-09 13:26:54 ./id_rsa.pub
   -rw-r--r-- tarek/staff   37192 2010-02-06 18:23:10 ./known_hosts


Archiving example with *base_dir*
---------------------------------

In this example, similar to the one above, we show how to use
"make_archive()", but this time with the usage of *base_dir*.  We now
have the following directory structure:

   $ tree tmp
   tmp
   └── root
       └── structure
           ├── content
               └── please_add.txt
           └── do_not_add.txt

In the final archive, "please_add.txt" should be included, but
"do_not_add.txt" should not.  Therefore we use the following:

   >>> from shutil import make_archive
   >>> import os
   >>> archive_name = os.path.expanduser(os.path.join('~', 'myarchive'))
   >>> make_archive(
   ...     archive_name,
   ...     'tar',
   ...     root_dir='tmp/root',
   ...     base_dir='structure/content',
   ... )
   '/Users/tarek/myarchive.tar'

Listing the files in the resulting archive gives us:

   $ python -m tarfile -l /Users/tarek/myarchive.tar
   structure/content/
   structure/content/please_add.txt


Querying the size of the output terminal
========================================

shutil.get_terminal_size(fallback=(columns, lines))

   Get the size of the terminal window.

   For each of the two dimensions, the environment variable, "COLUMNS"
   and "LINES" respectively, is checked. If the variable is defined
   and the value is a positive integer, it is used.

   When "COLUMNS" or "LINES" is not defined, which is the common case,
   the terminal connected to "sys.__stdout__" is queried by invoking
   "os.get_terminal_size()".

   If the terminal size cannot be successfully queried, either because
   the system doesn't support querying, or because we are not
   connected to a terminal, the value given in "fallback" parameter is
   used. "fallback" defaults to "(80, 24)" which is the default size
   used by many terminal emulators.

   The value returned is a named tuple of type "os.terminal_size".

   See also: The Single UNIX Specification, Version 2, Other
   Environment Variables.

   在 3.3 版被加入.

   在 3.11 版的變更: The "fallback" values are also used if
   "os.get_terminal_size()" returns zeroes.
