10.9. shutil — High-level file operations

Python 3.2.1

10.9. shutil — High-level file operations

Source code: 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.

Warning

Even the higher-level file copying functions (copy(), 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.

10.9.1. 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)

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 copy() for a copy that accepts a target directory path. If src and dst are the same files, Error is raised. The destination location must be writable; otherwise, an 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.

shutil.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.

shutil.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.

shutil.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.

shutil.copy2(src, dst)

Similar to copy(), but metadata is copied as well – in fact, this is just copy() followed by copystat(). This is similar to the Unix command cp -p.

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)

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 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; if false or omitted, the contents of the linked files are copied to the new tree.

When symlinks is false, if the file pointed by the symlink doesn’t exist, a exception will be added in the list of errors raised in a 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.

Changed in version 3.2: Added the copy_function argument to be able to provide a custom copy function.

Changed in version 3.2: Added the ignore_dangling_symlinks argument to silent dangling symlinks errors when symlinks is false.

shutil.rmtree(path, ignore_errors=False, onerror=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 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 os.path.islink(), os.listdir(), os.remove() or 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 sys.exc_info(). Exceptions raised by onerror will not be caught.

shutil.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 (with copy2()) to the dst and then remove src.

exception shutil.Error

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

10.9.1.1. copytree example

This example is the implementation of the 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)

Another 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)

10.9.2. Archiving operations

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”, “tar”, “bztar” (if the bz2 module is available) or “gztar”.

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.

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

logger is an instance of logging.Logger.

New in version 3.2.

shutil.get_archive_formats()

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

By default shutil provides these formats:

  • gztar: gzip’ed tar-file
  • bztar: bzip2’ed tar-file (if the bz2 module is available.)
  • tar: uncompressed tar file
  • zip: ZIP file

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

New in version 3.2.

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

Registers an archiver for the format name. function is a callable that will be used to invoke the archiver.

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 list.

New in version 3.2.

shutil.unregister_archive_format(name)

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

New in version 3.2.

shutil.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”, or “gztar”. 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.

New in version 3.2.

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, 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 get_unpack_formats() function.

New in version 3.2.

shutil.unregister_unpack_format(name)

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

New in version 3.2.

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:

  • gztar: gzip’ed tar-file
  • bztar: bzip2’ed tar-file (if the bz2 module is available.)
  • tar: uncompressed tar file
  • zip: ZIP file

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

New in version 3.2.

10.9.2.1. 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