kbe/src/lib/python/Doc/library/shutil.rst
shutil --- High-level file operations.. module:: shutil :synopsis: High-level file operations, including copying.
.. sectionauthor:: Fred L. Drake, Jr. [email protected] .. partly based on the docstrings
Source code: :source:Lib/shutil.py
.. index:: single: file; copying single: copying files
The :mod: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
:mod:os module.
.. warning::
Even the higher-level file copying functions (:func:shutil.copy,
:func: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.
.. _file-operations:
.. function:: 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.
.. function:: copyfile(src, dst, *, follow_symlinks=True)
Copy the contents (no metadata) of the file named src to a file named
dst and return dst. src and dst are path names given as strings.
dst must be the complete target file name; look at :func:shutil.copy
for a copy that accepts a target directory path. If src and dst
specify the same file, :exc:SameFileError is raised.
The destination location must be writable; otherwise, an :exc: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.
.. versionchanged:: 3.3
:exc:IOError used to be raised instead of :exc:OSError.
Added follow_symlinks argument.
Now returns dst.
.. versionchanged:: 3.4
Raise :exc:SameFileError instead of :exc:Error. Since the former is
a subclass of the latter, this change is backward compatible.
.. exception:: SameFileError
This exception is raised if source and destination in :func:copyfile
are the same file.
.. versionadded:: 3.4
.. function:: 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 names given as strings.
If follow_symlinks is false, and both src and dst are symbolic links,
:func: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 :func:copystat for more information. If
:func:copymode cannot modify symbolic links on the local platform, and it
is asked to do so, it will do nothing and return.
.. versionchanged:: 3.3 Added follow_symlinks argument.
.. function:: copystat(src, dst, *, follow_symlinks=True)
Copy the permission bits, last access time, last modification time, and
flags from src to dst. On Linux, :func:copystat also copies the
"extended attributes" where possible. The file contents, owner, and
group are unaffected. src and dst are path names given as strings.
If follow_symlinks is false, and src and dst both
refer to symbolic links, :func: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.
.. note::
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``, :func:`copystat` can modify the permission
bits of a symbolic link.
* If ``os.utime in os.supports_follow_symlinks`` is
``True``, :func:`copystat` can modify the last access
and modification times of a symbolic link.
* If ``os.chflags in os.supports_follow_symlinks`` is
``True``, :func:`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,
:func:`copystat` will copy everything it can.
:func:`copystat` never returns failure.
Please see :data:`os.supports_follow_symlinks`
for more information.
.. versionchanged:: 3.3 Added follow_symlinks argument and support for Linux extended attributes.
.. function:: copy(src, dst, *, follow_symlinks=True)
Copies the file src to the file or directory dst. src and dst should be strings. If dst specifies a directory, the file will be copied into dst using the base filename from src. 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.
:func:~shutil.copy copies the file data and the file's permission
mode (see :func:os.chmod). Other metadata, like the
file's creation and modification times, is not preserved.
To preserve all file metadata from the original, use
:func:~shutil.copy2 instead.
.. versionchanged:: 3.3 Added follow_symlinks argument. Now returns path to the newly created file.
.. function:: copy2(src, dst, *, follow_symlinks=True)
Identical to :func:~shutil.copy except that :func:copy2
also attempts to preserve file metadata.
When follow_symlinks is false, and src is a symbolic
link, :func: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, :func:copy2 will preserve all the metadata
it can; :func:copy2 never returns failure.
:func:copy2 uses :func:copystat to copy the file metadata.
Please see :func:copystat for more information
about platform support for modifying symbolic link metadata.
.. versionchanged:: 3.3 Added follow_symlinks argument, try to copy extended file system attributes too (currently Linux only). Now returns path to the newly created file.
.. function:: ignore_patterns(*patterns)
This factory function creates a function that can be used as a callable for
:func:copytree's ignore argument, ignoring files and directories that
match one of the glob-style patterns provided. See the example below.
.. function:: copytree(src, dst, symlinks=False, ignore=None,
copy_function=copy2, ignore_dangling_symlinks=False)
Recursively copy an entire directory tree rooted at src, returning the
destination directory. The destination
directory, named by dst, must not already exist; it will be created as
well as missing parent directories. Permissions and times of directories
are copied with :func:copystat, individual files are copied using
:func:shutil.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 by the symlink doesn't
exist, an exception will be added in the list of errors raised in
an :exc: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 :func:os.symlink.
If ignore is given, it must be a callable that will receive as its
arguments the directory being visited by :func:copytree, and a list of its
contents, as returned by :func:os.listdir. Since :func: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. :func:ignore_patterns can be used to create such a callable that
ignores names based on glob-style patterns.
If exception(s) occur, an :exc: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, :func:shutil.copy2 is used, but any function
that supports the same signature (like :func:shutil.copy) can be used.
.. versionchanged:: 3.3 Copy metadata when symlinks is false. Now returns dst.
.. versionchanged:: 3.2 Added the copy_function argument to be able to provide a custom copy function. Added the ignore_dangling_symlinks argument to silent dangling symlinks errors when symlinks is false.
.. function:: rmtree(path, ignore_errors=False, onerror=None)
.. index:: single: directory; deleting
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 onerror or, if that is omitted, they raise an exception.
.. note::
On platforms that support the necessary fd-based functions a symlink
attack resistant version of :func:`rmtree` is used by default. On other
platforms, the :func:`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 :data:`rmtree.avoids_symlink_attacks`
function attribute to determine which case applies.
If onerror 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, will be the exception information returned by
:func:sys.exc_info. Exceptions raised by onerror will not be caught.
.. versionchanged:: 3.3 Added a symlink attack resistant version that is used automatically if platform supports fd-based functions.
.. attribute:: rmtree.avoids_symlink_attacks
Indicates whether the current platform and implementation provides a
symlink attack resistant version of :func:`rmtree`. Currently this is
only true for platforms supporting fd-based directory access functions.
.. versionadded:: 3.3
.. function:: move(src, dst, copy_function=copy2)
Recursively move a file or directory (src) to another location (dst) and return the destination.
If the destination is an existing directory, then src is moved inside that
directory. If the destination already exists but is not a directory, it may
be overwritten depending on :func:os.rename semantics.
If the destination is on the current filesystem, then :func:os.rename is
used. Otherwise, src is copied to dst using copy_function and then
removed. In case of symlinks, a new symlink pointing to the target of src
will be created in or as dst and src will be removed.
If copy_function is given, it must be a callable that takes two arguments
src and dst, and will be used to copy src to dest if
:func:os.rename cannot be used. If the source is a directory,
:func:copytree is called, passing it the :func:copy_function. The
default copy_function is :func:copy2. Using :func:~shutil.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.
.. versionchanged:: 3.3
Added explicit symlink handling for foreign filesystems, thus adapting
it to the behavior of GNU's :program:mv.
Now returns dst.
.. versionchanged:: 3.5 Added the copy_function keyword argument.
.. function:: disk_usage(path)
Return disk usage statistics about the given path as a :term:named tuple
with the attributes total, used and free, which are the amount of
total, used and free space, in bytes. On Windows, path must be a
directory; on Unix, it can be a file or directory.
.. versionadded:: 3.3
.. availability:: Unix, Windows.
.. function:: chown(path, user=None, group=None)
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 :func:os.chown, the underlying function.
.. availability:: Unix.
.. versionadded:: 3.3
.. function:: 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 :func:os.access, by default
determining if the file exists and executable.
When no path is specified, the results of :func:os.environ are used,
returning either the "PATH" value or a fallback of :attr:os.defpath.
On Windows, the current directory is always prepended to the path whether
or not you use the default or provide your own, which is the behavior the
command shell uses when finding executables. Additionally, when finding the
cmd in the path, the PATHEXT environment variable is checked. For
example, if you call shutil.which("python"), :func: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'
.. versionadded:: 3.3
.. exception:: Error
This exception collects exceptions that are raised during a multi-file
operation. For :func:copytree, the exception argument is a list of 3-tuples
(srcname, dstname, exception).
.. _shutil-copytree-example:
copytree example
This example is the implementation of the :func:`copytree` function, described
above, with the docstring omitted. It demonstrates many of the other functions
provided by this module. ::
def copytree(src, dst, symlinks=False):
names = os.listdir(src)
os.makedirs(dst)
errors = []
for name in names:
srcname = os.path.join(src, name)
dstname = os.path.join(dst, name)
try:
if symlinks and os.path.islink(srcname):
linkto = os.readlink(srcname)
os.symlink(linkto, dstname)
elif os.path.isdir(srcname):
copytree(srcname, dstname, symlinks)
else:
copy2(srcname, dstname)
# XXX What about devices, sockets etc.?
except OSError as why:
errors.append((srcname, dstname, str(why)))
# catch the Error from the recursive copytree so that we can
# continue with other files
except Error as err:
errors.extend(err.args[0])
try:
copystat(src, dst)
except OSError as why:
# can't copy file access times on Windows
if why.winerror is None:
errors.extend((src, dst, str(why)))
if errors:
raise Error(errors)
Another example that uses the :func:`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)
.. _shutil-rmtree-example:
rmtree example
~~~~~~~~~~~~~~
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 onerror 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, onerror=remove_readonly)
.. _archiving-operations:
Archiving operations
--------------------
.. versionadded:: 3.2
.. versionchanged:: 3.5
Added support for the *xztar* format.
High-level utilities to create and read compressed and archived files are also
provided. They rely on the :mod:`zipfile` and :mod:`tarfile` modules.
.. function:: 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 :mod:`zlib` module is available), "tar", "gztar" (if the
:mod:`zlib` module is available), "bztar" (if the :mod:`bz2` module is
available), or "xztar" (if the :mod:`lzma` module is available).
*root_dir* is a directory that will be the root directory of the
archive; 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.
*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
:class:`logging.Logger`.
The *verbose* argument is unused and deprecated.
.. function:: get_archive_formats()
Return a list of supported formats for archiving.
Each element of the returned sequence is a tuple ``(name, description)``.
By default :mod:`shutil` provides these formats:
- *zip*: ZIP file (if the :mod:`zlib` module is available).
- *tar*: uncompressed tar file.
- *gztar*: gzip'ed tar-file (if the :mod:`zlib` module is available).
- *bztar*: bzip2'ed tar-file (if the :mod:`bz2` module is available).
- *xztar*: xz'ed tar-file (if the :mod:`lzma` module is available).
You can register new formats or provide your own archiver for any existing
formats, by using :func:`register_archive_format`.
.. function:: 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 :data:`os.curdir`) to start archiving from.
Further arguments are passed as keyword arguments: *owner*, *group*,
*dry_run* and *logger* (as passed in :func:`make_archive`).
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 :func:`get_archive_formats` which returns the
list of archivers. Defaults to an empty string.
.. function:: unregister_archive_format(name)
Remove the archive format *name* from the list of supported formats.
.. function:: unpack_archive(filename[, extract_dir[, format]])
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
:func:`register_unpack_format`. If not provided, :func:`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 :exc:`ValueError` is raised.
.. versionchanged:: 3.7
Accepts a :term:`path-like object` for *filename* and *extract_dir*.
.. function:: 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, followed by the directory
the archive must be extracted to.
When provided, *extra_args* is a sequence of ``(name, value)`` tuples that
will be passed as keywords arguments to the callable.
*description* can be provided to describe the format, and will be returned
by the :func:`get_unpack_formats` function.
.. function:: unregister_unpack_format(name)
Unregister an unpack format. *name* is the name of the format.
.. function:: 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 :mod:`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 :mod:`zlib` module is available).
- *bztar*: bzip2'ed tar-file (if the :mod:`bz2` module is available).
- *xztar*: xz'ed tar-file (if the :mod:`lzma` module is available).
You can register new formats or provide your own unpacker for any existing
formats, by using :func:`register_unpack_format`.
.. _shutil-archiving-example:
Archiving example
In this example, we create a gzip'ed tar-file archive containing all files
found in the :file:.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:
.. code-block:: shell-session
$ 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
.. function:: 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 :data:sys.__stdout__ is queried
by invoking :func: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 :class:os.terminal_size.
See also: The Single UNIX Specification, Version 2,
Other Environment Variables_.
.. versionadded:: 3.3
.. _Other Environment Variables:
http://pubs.opengroup.org/onlinepubs/7908799/xbd/envvar.html#tag_002_003