cpython/Doc/library/shutil.rst

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:mod:`shutil` --- High-level file operations
============================================
.. module:: shutil
:synopsis: High-level file operations, including copying.
.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
.. partly based on the docstrings
.. 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:`copy`, :func:`copy2`)
can't 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.
.. 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)
Copy the contents (no metadata) of the file named *src* to a file named *dst*.
*dst* must be the complete target file name; look at :func:`copy` for a copy that
accepts a target directory path. If *src* and *dst* are the same files,
:exc:`Error` is raised.
The destination location must be writable; otherwise, an :exc:`IOError` 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. *src* and *dst* are path names given as strings.
.. function:: copymode(src, dst)
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.
.. function:: copystat(src, dst)
Copy the permission bits, last access time, last modification time, and flags
from *src* to *dst*. The file contents, owner, and group are unaffected. *src*
and *dst* are path names given as strings.
.. function:: copy(src, dst)
Copy the file *src* to the file or directory *dst*. If *dst* is a directory, a
file with the same basename as *src* is created (or overwritten) in the
directory specified. Permission bits are copied. *src* and *dst* are path
names given as strings.
.. function:: copy2(src, dst)
Similar to :func:`copy`, but metadata is copied as well -- in fact, this is just
:func:`copy` followed by :func:`copystat`. This is similar to the
Unix command :program:`cp -p`.
.. 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]])
Recursively copy an entire directory tree rooted at *src*. 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:`copy2`.
If *symlinks* is true, symbolic links in the source tree are represented as
symbolic links in the new tree; if false or omitted, the contents of the
linked files are copied to the new tree.
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.
The source code for this should be considered an example rather than the
ultimate tool.
.. function:: rmtree(path[, ignore_errors[, onerror]])
.. 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.
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 will be
:func:`os.path.islink`, :func:`os.listdir`, :func:`os.remove` or
:func:`os.rmdir`. The second parameter, *path*, will be the path name passed
to *function*. The third parameter, *excinfo*, will be the exception
information return by :func:`sys.exc_info`. Exceptions raised by *onerror*
will not be caught.
.. function:: move(src, dst)
Recursively move a file or directory to another location.
If the destination is on the current filesystem, then simply use rename.
Otherwise, copy src to the dst and then remove src.
.. exception:: Error
This exception collects exceptions that raised during a multi-file operation. For
:func:`copytree`, the exception argument is a list of 3-tuples (*srcname*,
*dstname*, *exception*).
.. _shutil-example:
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 (IOError, os.error) 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 WindowsError:
# can't copy file access times on Windows
pass
except OSError as why:
errors.extend((src, dst, str(why)))
if errors:
raise Error(errors)