Usage examples of common file operation functions of shutil module in Python

The os module provides new/deleted/viewed file attributes for directories or files, and also provides path operations for files and directories. For example: absolute path, parent directory... However, the operations of os files should also include operations such as moving, copying, packaging, compression, and decompression. These os modules are not provided.
The shutdown discussed in this article is a supplement to file operations in os. --Move, copy, pack, compress and decompress,
shutil function function:
1 shutil.copyfileobj(fsrc, fdst[, length=16*1024])
Copy the content of the file to another file, and you can copy the content of a specified size
Let’s take a look at its source code first.

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

Attention! Among them, fsrc and fdst are both file objects, and they need to be opened before copying can be performed

import shutil
f1=open('name','r')
f2=open('name_copy','w+')
shutil.copyfileobj(f1,f2,length=16*1024)

2 shutil.copyfile(src,dst)
Copy the file content. Do you find it troublesome to copy the above files? You also need to manually open the file using the open function, which is not needed here. In fact, copyfile calls copyfileobj

def copyfile(src, dst, *, follow_symlinks=True):
  if _samefile(src, dst):
    raise SameFileError("{!r} and {!r} are the same file".format(src, dst))
  for fn in [src, dst]:
    try:
      st = os.stat(fn)
    except OSError:
      # File most likely does not exist
      pass
    else:
      # XXX What about other special files? (sockets, devices...)
      if stat.S_ISFIFO(st.st_mode):
        raise SpecialFileError("`%s` is a named pipe" % fn)
  if not follow_symlinks and os.path.islink(src):
    os.symlink(os.readlink(src), dst)
  else:
    with open(src, 'rb') as fsrc:
      with open(dst, 'wb') as fdst:
        copyfileobj(fsrc, fdst)
  return dst

shutil.copyfile('name','name_copy_2')
#一句就可以实现复制文件内容

3 shutil.copymode(src,dst)
Copy permission only, no changes to file content, groups and users.

def copymode(src, dst, *, follow_symlinks=True):
  if not follow_symlinks and os.path.islink(src) and os.path.islink(dst):
    if hasattr(os, 'lchmod'):
      stat_func, chmod_func = os.lstat, os.lchmod
    else:
      return
  elif hasattr(os, 'chmod'):
    stat_func, chmod_func = os.stat, os.chmod
  else:
    return
  st = stat_func(src)
  chmod_func(dst, stat.S_IMODE(st.st_mode))

Look at the permissions of the two files first

[root@slyoyo python_test]# ls -l
total 4
-rw-r--r--. 1 root root 79 May 14 05:17 test1
-rwxr-xr-x. 1 root root 0 May 14 19:10 test2

Run command

>>> import shutil
>>> shutil.copymode('test1','test2')

View results

[root@slyoyo python_test]# ls -l
total 4
-rw-r--r--. 1 root root 79 May 14 05:17 test1
-rw-r--r--. 1 root root 0 May 14 19:10 test2

When we replace the target file with a non-existent file, an error occurs

>>> shutil.copymode('test1','test3')  
Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
 File "/usr/local/python/lib/python3.4/shutil.py", line 132, in copymode
  chmod_func(dst, stat.S_IMODE(st.st_mode))
FileNotFoundError: [Errno 2] No such file or directory: 'test233'

4 shutil.copystat(src,dst)
Copy all status information, including permissions, groups, users, time, etc.

def copystat(src, dst, *, follow_symlinks=True):

  def _nop(*args, ns=None, follow_symlinks=None):
    pass
  # follow symlinks (aka don't not follow symlinks)
  follow = follow_symlinks or not (os.path.islink(src) and os.path.islink(dst))
  if follow:
    # use the real function if it exists
    def lookup(name):
      return getattr(os, name, _nop)
  else:
    # use the real function only if it exists
    # *and* it supports follow_symlinks
    def lookup(name):
      fn = getattr(os, name, _nop)
      if fn in os.supports_follow_symlinks:
        return fn
      return _nop
  st = lookup("stat")(src, follow_symlinks=follow)
  mode = stat.S_IMODE(st.st_mode)
  lookup("utime")(dst, ns=(st.st_atime_ns, st.st_mtime_ns),
    follow_symlinks=follow)
  try:
    lookup("chmod")(dst, mode, follow_symlinks=follow)
  except NotImplementedError:
    # if we got a NotImplementedError, it's because
    #  * follow_symlinks=False,
    #  * lchown() is unavailable, and
    #  * either
    #    * fchownat() is unavailable or
    #    * fchownat() doesn't implement AT_SYMLINK_NOFOLLOW.
    #     (it returned ENOSUP.)
    # therefore we're out of options--we simply cannot chown the
    # symlink. give up, suppress the error.
    # (which is what shutil always did in this circumstance.)
    pass
  if hasattr(st, 'st_flags'):
    try:
      lookup("chflags")(dst, st.st_flags, follow_symlinks=follow)
    except OSError as why:
      for err in 'EOPNOTSUPP', 'ENOTSUP':
        if hasattr(errno, err) and why.errno == getattr(errno, err):
          break
      else:
        raise
  _copyxattr(src, dst, follow_symlinks=follow)

5 shutil.copy(src,dst)
Copy the content and permissions of the file, copyfile first and then copymode

 def copy(src, dst, *, follow_symlinks=True):

  if os.path.isdir(dst):
    dst = os.path.join(dst, os.path.basename(src))
  copyfile(src, dst, follow_symlinks=follow_symlinks)
  copymode(src, dst, follow_symlinks=follow_symlinks)
  return dst

6 shutil.copy2(src,dst)
Copy the contents of the file as well as all of the file's status information. Copyfile first and then copystat

def copy2(src, dst, *, follow_symlinks=True):
  """Copy data and all stat info ("cp -p src dst"). Return the file's
  destination."
  The destination may be a directory.
  If follow_symlinks is false, symlinks won't be followed. This
  resembles GNU's "cp -P src dst".
  """
  if os.path.isdir(dst):
    dst = os.path.join(dst, os.path.basename(src))
  copyfile(src, dst, follow_symlinks=follow_symlinks)
  copystat(src, dst, follow_symlinks=follow_symlinks)
  return dst

7 shutil.copytree(src, dst, symlinks=False, ignore=None, copy_function=copy2,ignore_dangling_symlinks=False)
Recursively copy file content and status information

def copytree(src, dst, symlinks=False, ignore=None, copy_function=copy2,
       ignore_dangling_symlinks=False):

  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 os.path.islink(srcname):
        linkto = os.readlink(srcname)
        if symlinks:
          # We can't just leave it to `copy_function` because legacy
          # code with a custom `copy_function` may rely on copytree
          # doing the right thing.
          os.symlink(linkto, dstname)
          copystat(srcname, dstname, follow_symlinks=not symlinks)
        else:
          # ignore dangling symlink if the flag is on
          if not os.path.exists(linkto) and ignore_dangling_symlinks:
            continue
          # otherwise let the copy occurs. copy2 will raise an error
          if os.path.isdir(srcname):
            copytree(srcname, dstname, symlinks, ignore,
                 copy_function)
          else:
            copy_function(srcname, dstname)
      elif os.path.isdir(srcname):
        copytree(srcname, dstname, symlinks, ignore, copy_function)
      else:
        # Will raise a SpecialFileError for unsupported file types
        copy_function(srcname, dstname)
    # catch the Error from the recursive copytree so that we can
    # continue with other files
    except Error as err:
      errors.extend(err.args[0])
    except OSError as why:
      errors.append((srcname, dstname, str(why)))
  try:
    copystat(src, dst)
  except OSError as why:
    # Copying file access times may fail on Windows
    if getattr(why, 'winerror', None) is None:
      errors.append((src, dst, str(why)))
  if errors:
    raise Error(errors)
  return dst
# version vulnerable to race conditions

[root@slyoyo python_test]# tree copytree_test/
copytree_test/
└── test
  ├── test1
  ├── test2
  └── hahaha
[root@slyoyo test]# ls -l
total 0
-rw-r--r--. 1 python python 0 May 14 19:36 hahaha
-rw-r--r--. 1 python python 0 May 14 19:36 test1
-rw-r--r--. 1 root  root  0 May 14 19:36 test2
>>> shutil.copytree('copytree_test','copytree_copy')
'copytree_copy'
[root@slyoyo python_test]# ls -l
total 12
drwxr-xr-x. 3 root  root  4096 May 14 19:36 copytree_copy
drwxr-xr-x. 3 root  root  4096 May 14 19:36 copytree_test
-rw-r--r--. 1 python python  79 May 14 05:17 test1
-rw-r--r--. 1 root  root   0 May 14 19:10 test2
[root@slyoyo python_test]# tree copytree_copy/
copytree_copy/
└── test
  ├── hahaha
  ├── test1
  └── test2

8 shutil.rmtree(path, ignore_errors=False, onerror=None)
Delete files recursively

def rmtree(path, ignore_errors=False, onerror=None):

  if ignore_errors:
    def onerror(*args):
      pass
  elif onerror is None:
    def onerror(*args):
      raise
  if _use_fd_functions:
    # While the unsafe rmtree works fine on bytes, the fd based does not.
    if isinstance(path, bytes):
      path = os.fsdecode(path)
    # Note: To guard against symlink races, we use the standard
    # lstat()/open()/fstat() trick.
    try:
      orig_st = os.lstat(path)
    except Exception:
      onerror(os.lstat, path, sys.exc_info())
      return
    try:
      fd = os.open(path, os.O_RDONLY)
    except Exception:
      onerror(os.lstat, path, sys.exc_info())
      return
    try:
      if os.path.samestat(orig_st, os.fstat(fd)):
        _rmtree_safe_fd(fd, path, onerror)
        try:
          os.rmdir(path)
        except OSError:
          onerror(os.rmdir, path, sys.exc_info())
      else:
        try:
          # symlinks to directories are forbidden, see bug #1669
          raise OSError("Cannot call rmtree on a symbolic link")
        except OSError:
          onerror(os.path.islink, path, sys.exc_info())
    finally:
      os.close(fd)
  else:
    return _rmtree_unsafe(path, onerror)

9 shutil.move(src, dst)
Move files recursively

def move(src, dst):

  real_dst = dst
  if os.path.isdir(dst):
    if _samefile(src, dst):
      # We might be on a case insensitive filesystem,
      # perform the rename anyway.
      os.rename(src, dst)
      return
    real_dst = os.path.join(dst, _basename(src))
    if os.path.exists(real_dst):
      raise Error("Destination path '%s' already exists" % real_dst)
  try:
    os.rename(src, real_dst)
  except OSError:
    if os.path.islink(src):
      linkto = os.readlink(src)
      os.symlink(linkto, real_dst)
      os.unlink(src)
    elif os.path.isdir(src):
      if _destinsrc(src, dst):
        raise Error("Cannot move a directory '%s' into itself '%s'." % (src, dst))
      copytree(src, real_dst, symlinks=True)
      rmtree(src)
    else:
      copy2(src, real_dst)
      os.unlink(src)
  return real_dst

10 make_archive(base_name, format, root_dir=None, base_dir=None, verbose=0,dry_run=0, owner=None, group=None, logger=None)

Compressed and packaged

def make_archive(base_name, format, root_dir=None, base_dir=None, verbose=0,
         dry_run=0, owner=None, group=None, logger=None):

  save_cwd = os.getcwd()
  if root_dir is not None:
    if logger is not None:
      logger.debug("changing into '%s'", root_dir)
    base_name = os.path.abspath(base_name)
    if not dry_run:
      os.chdir(root_dir)
  if base_dir is None:
    base_dir = os.curdir
  kwargs = {'dry_run': dry_run, 'logger': logger}
  try:
    format_info = _ARCHIVE_FORMATS[format]
  except KeyError:
    raise ValueError("unknown archive format '%s'" % format)
  func = format_info[0]
  for arg, val in format_info[1]:
    kwargs[arg] = val
  if format != 'zip':
    kwargs['owner'] = owner
    kwargs['group'] = group
  try:
    filename = func(base_name, base_dir, **kwargs)
  finally:
    if root_dir is not None:
      if logger is not None:
        logger.debug("changing back to '%s'", save_cwd)
      os.chdir(save_cwd)
  return filename

base_name: The compressed file name or path name
format: Compression or packaging format "zip", "tar", "bztar" or "gztar"
root_dir: Which directory or file to package (that is, the source file)

>>> shutil.make_archive('tarball','gztar',root_dir='copytree_test')
[root@slyoyo python_test]# ls -l
total 12
drwxr-xr-x. 3 root  root  4096 May 14 19:36 copytree_copy
drwxr-xr-x. 3 root  root  4096 May 14 19:36 copytree_test
-rw-r--r--. 1 root  root   0 May 14 21:12 tarball.tar.gz
-rw-r--r--. 1 python python  79 May 14 05:17 test1
-rw-r--r--. 1 root  root   0 May 14 19:10 test2