10.10. shutil — Opérations de haut niveau sur les fichiers

Code source : Lib/shutil.py


Le module shutil propose des opérations de haut niveau sur les fichiers et ensembles de fichiers. En particulier, des fonctions pour copier et déplacer les fichiers sont proposées. Pour les opérations individuelles sur les fichiers, reportez-vous au module os.

Avertissement

Even the higher-level file copying functions (shutil.copy(), shutil.copy2()) can’t copy all file metadata.

Sur les plateformes POSIX, cela signifie que le propriétaire et le groupe du fichier sont perdus, ainsi que les ACLs. Sur Mac OS, le clonage de ressource et autres métadonnées ne sont pas utilisés. Cela signifie que les ressources seront perdues et que le type de fichier et les codes créateur ne seront pas corrects. Sur Windows, les propriétaires des fichiers, ACLs et flux de données alternatifs ne sont pas copiés.

10.10.1. Opérations sur les répertoires et les fichiers

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

Copie le contenu de l’objet fichier fsrc dans l’objet fichier fdst. L’entier length, si spécifié, est la taille du tampon. En particulier, une valeur de length négative signifie la copie des données sans découper la source en morceaux ; par défaut les données sont lues par morceaux pour éviter la consommation mémoire non-contrôlée. À noter que si la position courante dans l’objet fsrc n’est pas 0, seul le contenu depuis la position courante jusqu’à la fin est copié.

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 shutil.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)

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

copy2() uses copystat() to copy the file metadata. Please see copystat() for more information.

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.

Nouveau dans la version 2.6.

shutil.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 copystat(), individual files are copied using shutil.copy2().

If symlinks is true, symbolic links in the source tree are represented as symbolic links in the new tree, but the metadata of the original links is NOT copied; if false or omitted, the contents and metadata 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 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.

The source code for this should be considered an example rather than the ultimate tool.

Modifié dans la version 2.3: Error is raised if any exceptions occur during copying, rather than printing a message.

Modifié dans la version 2.5: Create intermediate directories needed to create dst, rather than raising an error. Copy permissions and times of directories using copystat().

Modifié dans la version 2.6: Added the ignore argument to be able to influence what is being copied.

shutil.rmtree(path[, ignore_errors[, onerror]])

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.

Modifié dans la version 2.6: Explicitly check for path being a symbolic link and raise OSError in that case.

shutil.move(src, dst)

Recursively move a file or directory (src) to another location (dst).

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 os.rename() semantics.

If the destination is on the current filesystem, then os.rename() is used. Otherwise, src is copied (using shutil.copy2()) to dst and then removed.

Nouveau dans la version 2.3.

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).

Nouveau dans la version 2.3.

10.10.1.1. 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, ignore=None):
    names = os.listdir(src)
    if ignore is not None:
        ignored_names = ignore(src, names)
    else:
        ignored_names = set()

    os.makedirs(dst)
    errors = []
    for name in names:
        if name in ignored_names:
            continue
        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, ignore)
            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)

10.10.2. Archiving operations

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 (eg. zip or tar) and returns 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 or external zip executable is available), « tar », « gztar » (if the zlib module is available), or « bztar » (if the bz2 module is available).

root_dir is a directory that will be the root directory of the archive; ie. we typically chdir into root_dir before creating the archive.

base_dir is the directory where we start archiving from; ie. 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 must be an object compatible with PEP 282, usually an instance of logging.Logger.

Nouveau dans la version 2.7.

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 or external zip executable 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).

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

Nouveau dans la version 2.7.

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

Register 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) 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.

Nouveau dans la version 2.7.

shutil.unregister_archive_format(name)

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

Nouveau dans la version 2.7.

10.10.2.1. 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