Python3 shutil模块

1 def copyfileobj(fsrc, fdst, length=16*1024):
2     """copy data from file-like object fsrc to file-like object fdst"""
3     while 1:
4         buf = fsrc.read(length)
5         if not buf:
6             break
7         fdst.write(buf)

 1 def copyfile(src, dst, *, follow_symlinks=True):
 2     """Copy data from src to dst.
 3 
 4     If follow_symlinks is not set and src is a symbolic link, a new
 5     symlink will be created instead of copying the file it points to.
 6 
 7     """
 8     if _samefile(src, dst):
 9         raise SameFileError("{!r} and {!r} are the same file".format(src, dst))
10 
11     for fn in [src, dst]:
12         try:
13             st = os.stat(fn)
14         except OSError:
15             # File most likely does not exist
16             pass
17         else:
18             # XXX What about other special files? (sockets, devices...)
19             if stat.S_ISFIFO(st.st_mode):
20                 raise SpecialFileError("`%s` is a named pipe" % fn)
21 
22     if not follow_symlinks and os.path.islink(src):
23         os.symlink(os.readlink(src), dst)
24     else:
25         with open(src, ‘rb‘) as fsrc:
26             with open(dst, ‘wb‘) as fdst:
27                 copyfileobj(fsrc, fdst)
28     return dst

 1 def copymode(src, dst, *, follow_symlinks=True):
 2     """Copy mode bits from src to dst.
 3 
 4     If follow_symlinks is not set, symlinks aren‘t followed if and only
 5     if both `src` and `dst` are symlinks.  If `lchmod` isn‘t available
 6     (e.g. Linux) this method does nothing.
 7 
 8     """
 9     if not follow_symlinks and os.path.islink(src) and os.path.islink(dst):
10         if hasattr(os, ‘lchmod‘):
11             stat_func, chmod_func = os.lstat, os.lchmod
12         else:
13             return
14     elif hasattr(os, ‘chmod‘):
15         stat_func, chmod_func = os.stat, os.chmod
16     else:
17         return
18 
19     st = stat_func(src)
20     chmod_func(dst, stat.S_IMODE(st.st_mode))

 1 def copystat(src, dst, *, follow_symlinks=True):
 2     """Copy all stat info (mode bits, atime, mtime, flags) from src to dst.
 3 
 4     If the optional flag `follow_symlinks` is not set, symlinks aren‘t followed if and
 5     only if both `src` and `dst` are symlinks.
 6 
 7     """
 8     def _nop(*args, ns=None, follow_symlinks=None):
 9         pass
10 
11     # follow symlinks (aka don‘t not follow symlinks)
12     follow = follow_symlinks or not (os.path.islink(src) and os.path.islink(dst))
13     if follow:
14         # use the real function if it exists
15         def lookup(name):
16             return getattr(os, name, _nop)
17     else:
18         # use the real function only if it exists
19         # *and* it supports follow_symlinks
20         def lookup(name):
21             fn = getattr(os, name, _nop)
22             if fn in os.supports_follow_symlinks:
23                 return fn
24             return _nop
25 
26     st = lookup("stat")(src, follow_symlinks=follow)
27     mode = stat.S_IMODE(st.st_mode)
28     lookup("utime")(dst, ns=(st.st_atime_ns, st.st_mtime_ns),
29         follow_symlinks=follow)
30     try:
31         lookup("chmod")(dst, mode, follow_symlinks=follow)
32     except NotImplementedError:
33         # if we got a NotImplementedError, it‘s because
34         #   * follow_symlinks=False,
35         #   * lchown() is unavailable, and
36         #   * either
37         #       * fchownat() is unavailable or
38         #       * fchownat() doesn‘t implement AT_SYMLINK_NOFOLLOW.
39         #         (it returned ENOSUP.)
40         # therefore we‘re out of options--we simply cannot chown the
41         # symlink.  give up, suppress the error.
42         # (which is what shutil always did in this circumstance.)
43         pass
44     if hasattr(st, ‘st_flags‘):
45         try:
46             lookup("chflags")(dst, st.st_flags, follow_symlinks=follow)
47         except OSError as why:
48             for err in ‘EOPNOTSUPP‘, ‘ENOTSUP‘:
49                 if hasattr(errno, err) and why.errno == getattr(errno, err):
50                     break
51             else:
52                 raise
53     _copyxattr(src, dst, follow_symlinks=follow)

 1 def copy(src, dst, *, follow_symlinks=True):
 2     """Copy data and mode bits ("cp src dst"). Return the file‘s destination.
 3 
 4     The destination may be a directory.
 5 
 6     If follow_symlinks is false, symlinks won‘t be followed. This
 7     resembles GNU‘s "cp -P src dst".
 8 
 9     If source and destination are the same file, a SameFileError will be
10     raised.
11 
12     """
13     if os.path.isdir(dst):
14         dst = os.path.join(dst, os.path.basename(src))
15     copyfile(src, dst, follow_symlinks=follow_symlinks)
16     copymode(src, dst, follow_symlinks=follow_symlinks)
17     return dst

 1 def copy2(src, dst, *, follow_symlinks=True):
 2     """Copy data and all stat info ("cp -p src dst"). Return the file‘s
 3     destination."
 4 
 5     The destination may be a directory.
 6 
 7     If follow_symlinks is false, symlinks won‘t be followed. This
 8     resembles GNU‘s "cp -P src dst".
 9 
10     """
11     if os.path.isdir(dst):
12         dst = os.path.join(dst, os.path.basename(src))
13     copyfile(src, dst, follow_symlinks=follow_symlinks)
14     copystat(src, dst, follow_symlinks=follow_symlinks)
15     return dst

 1 def ignore_patterns(*patterns):
 2     """Function that can be used as copytree() ignore parameter.
 3 
 4     Patterns is a sequence of glob-style patterns
 5     that are used to exclude files"""
 6     def _ignore_patterns(path, names):
 7         ignored_names = []
 8         for pattern in patterns:
 9             ignored_names.extend(fnmatch.filter(names, pattern))
10         return set(ignored_names)
11     return _ignore_patterns

 1 def copytree(src, dst, symlinks=False, ignore=None, copy_function=copy2,
 2              ignore_dangling_symlinks=False):
 3     """Recursively copy a directory tree.
 4 
 5     The destination directory must not already exist.
 6     If exception(s) occur, an Error is raised with a list of reasons.
 7 
 8     If the optional symlinks flag is true, symbolic links in the
 9     source tree result in symbolic links in the destination tree; if
10     it is false, the contents of the files pointed to by symbolic
11     links are copied. If the file pointed by the symlink doesn‘t
12     exist, an exception will be added in the list of errors raised in
13     an Error exception at the end of the copy process.
14 
15     You can set the optional ignore_dangling_symlinks flag to true if you
16     want to silence this exception. Notice that this has no effect on
17     platforms that don‘t support os.symlink.
18 
19     The optional ignore argument is a callable. If given, it
20     is called with the `src` parameter, which is the directory
21     being visited by copytree(), and `names` which is the list of
22     `src` contents, as returned by os.listdir():
23 
24         callable(src, names) -> ignored_names
25 
26     Since copytree() is called recursively, the callable will be
27     called once for each directory that is copied. It returns a
28     list of names relative to the `src` directory that should
29     not be copied.
30 
31     The optional copy_function argument is a callable that will be used
32     to copy each file. It will be called with the source path and the
33     destination path as arguments. By default, copy2() is used, but any
34     function that supports the same signature (like copy()) can be used.
35 
36     """
37     names = os.listdir(src)
38     if ignore is not None:
39         ignored_names = ignore(src, names)
40     else:
41         ignored_names = set()
42 
43     os.makedirs(dst)
44     errors = []
45     for name in names:
46         if name in ignored_names:
47             continue
48         srcname = os.path.join(src, name)
49         dstname = os.path.join(dst, name)
50         try:
51             if os.path.islink(srcname):
52                 linkto = os.readlink(srcname)
53                 if symlinks:
54                     # We can‘t just leave it to `copy_function` because legacy
55                     # code with a custom `copy_function` may rely on copytree
56                     # doing the right thing.
57                     os.symlink(linkto, dstname)
58                     copystat(srcname, dstname, follow_symlinks=not symlinks)
59                 else:
60                     # ignore dangling symlink if the flag is on
61                     if not os.path.exists(linkto) and ignore_dangling_symlinks:
62                         continue
63                     # otherwise let the copy occurs. copy2 will raise an error
64                     if os.path.isdir(srcname):
65                         copytree(srcname, dstname, symlinks, ignore,
66                                  copy_function)
67                     else:
68                         copy_function(srcname, dstname)
69             elif os.path.isdir(srcname):
70                 copytree(srcname, dstname, symlinks, ignore, copy_function)
71             else:
72                 # Will raise a SpecialFileError for unsupported file types
73                 copy_function(srcname, dstname)
74         # catch the Error from the recursive copytree so that we can
75         # continue with other files
76         except Error as err:
77             errors.extend(err.args[0])
78         except OSError as why:
79             errors.append((srcname, dstname, str(why)))
80     try:
81         copystat(src, dst)
82     except OSError as why:
83         # Copying file access times may fail on Windows
84         if getattr(why, ‘winerror‘, None) is None:
85             errors.append((src, dst, str(why)))
86     if errors:
87         raise Error(errors)
88     return dst
89 
90 # version vulnerable to race conditions

 1 def rmtree(path, ignore_errors=False, onerror=None):
 2     """Recursively delete a directory tree.
 3 
 4     If ignore_errors is set, errors are ignored; otherwise, if onerror
 5     is set, it is called to handle the error with arguments (func,
 6     path, exc_info) where func is platform and implementation dependent;
 7     path is the argument to that function that caused it to fail; and
 8     exc_info is a tuple returned by sys.exc_info().  If ignore_errors
 9     is false and onerror is None, an exception is raised.
10 
11     """
12     if ignore_errors:
13         def onerror(*args):
14             pass
15     elif onerror is None:
16         def onerror(*args):
17             raise
18     if _use_fd_functions:
19         # While the unsafe rmtree works fine on bytes, the fd based does not.
20         if isinstance(path, bytes):
21             path = os.fsdecode(path)
22         # Note: To guard against symlink races, we use the standard
23         # lstat()/open()/fstat() trick.
24         try:
25             orig_st = os.lstat(path)
26         except Exception:
27             onerror(os.lstat, path, sys.exc_info())
28             return
29         try:
30             fd = os.open(path, os.O_RDONLY)
31         except Exception:
32             onerror(os.lstat, path, sys.exc_info())
33             return
34         try:
35             if os.path.samestat(orig_st, os.fstat(fd)):
36                 _rmtree_safe_fd(fd, path, onerror)
37                 try:
38                     os.rmdir(path)
39                 except OSError:
40                     onerror(os.rmdir, path, sys.exc_info())
41             else:
42                 try:
43                     # symlinks to directories are forbidden, see bug #1669
44                     raise OSError("Cannot call rmtree on a symbolic link")
45                 except OSError:
46                     onerror(os.path.islink, path, sys.exc_info())
47         finally:
48             os.close(fd)
49     else:
50         return _rmtree_unsafe(path, onerror)

 1 def move(src, dst, copy_function=copy2):
 2     """Recursively move a file or directory to another location. This is
 3     similar to the Unix "mv" command. Return the file or directory‘s
 4     destination.
 5 
 6     If the destination is a directory or a symlink to a directory, the source
 7     is moved inside the directory. The destination path must not already
 8     exist.
 9 
10     If the destination already exists but is not a directory, it may be
11     overwritten depending on os.rename() semantics.
12 
13     If the destination is on our current filesystem, then rename() is used.
14     Otherwise, src is copied to the destination and then removed. Symlinks are
15     recreated under the new name if os.rename() fails because of cross
16     filesystem renames.
17 
18     The optional `copy_function` argument is a callable that will be used
19     to copy the source or it will be delegated to `copytree`.
20     By default, copy2() is used, but any function that supports the same
21     signature (like copy()) can be used.
22 
23     A lot more could be done here...  A look at a mv.c shows a lot of
24     the issues this implementation glosses over.
25 
26     """
27     real_dst = dst
28     if os.path.isdir(dst):
29         if _samefile(src, dst):
30             # We might be on a case insensitive filesystem,
31             # perform the rename anyway.
32             os.rename(src, dst)
33             return
34 
35         real_dst = os.path.join(dst, _basename(src))
36         if os.path.exists(real_dst):
37             raise Error("Destination path ‘%s‘ already exists" % real_dst)
38     try:
39         os.rename(src, real_dst)
40     except OSError:
41         if os.path.islink(src):
42             linkto = os.readlink(src)
43             os.symlink(linkto, real_dst)
44             os.unlink(src)
45         elif os.path.isdir(src):
46             if _destinsrc(src, dst):
47                 raise Error("Cannot move a directory ‘%s‘ into itself"
48                             " ‘%s‘." % (src, dst))
49             copytree(src, real_dst, copy_function=copy_function,
50                      symlinks=True)
51             rmtree(src)
52         else:
53             copy_function(src, real_dst)
54             os.unlink(src)
55     return real_dst

1 def get_archive_formats():
2     """Returns a list of supported formats for archiving and unarchiving.
3 
4     Each element of the returned sequence is a tuple (name, description)
5     """
6     formats = [(name, registry[2]) for name, registry in
7                _ARCHIVE_FORMATS.items()]
8     formats.sort()
9     return formats

 1 def register_archive_format(name, function, extra_args=None, description=‘‘):
 2     """Registers an archive format.
 3 
 4     name is the name of the format. function is the callable that will be
 5     used to create archives. If provided, extra_args is a sequence of
 6     (name, value) tuples that will be passed as arguments to the callable.
 7     description can be provided to describe the format, and will be returned
 8     by the get_archive_formats() function.
 9     """
10     if extra_args is None:
11         extra_args = []
12     if not callable(function):
13         raise TypeError(‘The %s object is not callable‘ % function)
14     if not isinstance(extra_args, (tuple, list)):
15         raise TypeError(‘extra_args needs to be a sequence‘)
16     for element in extra_args:
17         if not isinstance(element, (tuple, list)) or len(element) !=2:
18             raise TypeError(‘extra_args elements are : (arg_name, value)‘)
19 
20     _ARCHIVE_FORMATS[name] = (function, extra_args, description)

 1 def make_archive(base_name, format, root_dir=None, base_dir=None, verbose=0,
 2                  dry_run=0, owner=None, group=None, logger=None):
 3     """Create an archive file (eg. zip or tar).
 4 
 5     ‘base_name‘ is the name of the file to create, minus any format-specific
 6     extension; ‘format‘ is the archive format: one of "zip", "tar", "bztar"
 7     or "gztar".
 8 
 9     ‘root_dir‘ is a directory that will be the root directory of the
10     archive; ie. we typically chdir into ‘root_dir‘ before creating the
11     archive.  ‘base_dir‘ is the directory where we start archiving from;
12     ie. ‘base_dir‘ will be the common prefix of all files and
13     directories in the archive.  ‘root_dir‘ and ‘base_dir‘ both default
14     to the current directory.  Returns the name of the archive file.
15 
16     ‘owner‘ and ‘group‘ are used when creating a tar archive. By default,
17     uses the current owner and group.
18     """
19     save_cwd = os.getcwd()
20     if root_dir is not None:
21         if logger is not None:
22             logger.debug("changing into ‘%s‘", root_dir)
23         base_name = os.path.abspath(base_name)
24         if not dry_run:
25             os.chdir(root_dir)
26 
27     if base_dir is None:
28         base_dir = os.curdir
29 
30     kwargs = {‘dry_run‘: dry_run, ‘logger‘: logger}
31 
32     try:
33         format_info = _ARCHIVE_FORMATS[format]
34     except KeyError:
35         raise ValueError("unknown archive format ‘%s‘" % format)
36 
37     func = format_info[0]
38     for arg, val in format_info[1]:
39         kwargs[arg] = val
40 
41     if format != ‘zip‘:
42         kwargs[‘owner‘] = owner
43         kwargs[‘group‘] = group
44 
45     try:
46         filename = func(base_name, base_dir, **kwargs)
47     finally:
48         if root_dir is not None:
49             if logger is not None:
50                 logger.debug("changing back to ‘%s‘", save_cwd)
51             os.chdir(save_cwd)
52 
53     return filename

 1 def unpack_archive(filename, extract_dir=None, format=None):
 2     """Unpack an archive.
 3 
 4     `filename` is the name of the archive.
 5 
 6     `extract_dir` is the name of the target directory, where the archive
 7     is unpacked. If not provided, the current working directory is used.
 8 
 9     `format` is the archive format: one of "zip", "tar", or "gztar". Or any
10     other registered format. If not provided, unpack_archive will use the
11     filename extension and see if an unpacker was registered for that
12     extension.
13 
14     In case none is found, a ValueError is raised.
15     """
16     if extract_dir is None:
17         extract_dir = os.getcwd()
18 
19     if format is not None:
20         try:
21             format_info = _UNPACK_FORMATS[format]
22         except KeyError:
23             raise ValueError("Unknown unpack format ‘{0}‘".format(format))
24 
25         func = format_info[1]
26         func(filename, extract_dir, **dict(format_info[2]))
27     else:
28         # we need to look at the registered unpackers supported extensions
29         format = _find_unpack_format(filename)
30         if format is None:
31             raise ReadError("Unknown archive format ‘{0}‘".format(filename))
32 
33         func = _UNPACK_FORMATS[format][1]
34         kwargs = dict(_UNPACK_FORMATS[format][2])
35         func(filename, extract_dir, **kwargs)

 1 def chown(path, user=None, group=None):
 2     """Change owner user and group of the given path.
 3 
 4     user and group can be the uid/gid or the user/group names, and in that case,
 5     they are converted to their respective uid/gid.
 6     """
 7 
 8     if user is None and group is None:
 9         raise ValueError("user and/or group must be set")
10 
11     _user = user
12     _group = group
13 
14     # -1 means don‘t change it
15     if user is None:
16         _user = -1
17     # user can either be an int (the uid) or a string (the system username)
18     elif isinstance(user, str):
19         _user = _get_uid(user)
20         if _user is None:
21             raise LookupError("no such user: {!r}".format(user))
22 
23     if group is None:
24         _group = -1
25     elif not isinstance(group, int):
26         _group = _get_gid(group)
27         if _group is None:
28             raise LookupError("no such group: {!r}".format(group))
29 
30     os.chown(path, _user, _group)