Python中shutil模块的常用文件操作函数用法示例
os模块提供了对目录或者文件的新建/删除/查看文件属性，还提供了对文件以及目录的路径操作。比如说：绝对路径，父目录…… 但是，os文件的操作还应该包含移动 复制 打包 压缩 解压等操作，这些os模块都没有提供。
而本文所讲的shutil则就是对os中文件操作的补充。--移动 复制 打包 压缩 解压，
shutil函数功能：
1 shutil.copyfileobj(fsrc, fdst[, length=16*1024])
copy文件内容到另一个文件，可以copy指定大小的内容
先来看看其源代码。
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)
注意！ 在其中fsrc，fdst都是文件对象，都需要打开后才能进行复制操作
import shutil
f1=open('name','r')
f2=open('name_copy','w+')
shutil.copyfileobj(f1,f2,length=16*1024)
2 shutil.copyfile(src,dst)
copy文件内容，是不是感觉上面的文件复制很麻烦？还需要自己手动用open函数打开文件，在这里就不需要了，事实上，copyfile调用了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)
仅copy权限，不更改文件内容，组和用户。
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))
先看两个文件的权限
[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
运行命令
>>> import shutil
>>> shutil.copymode('test1','test2')
查看结果
[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
当我们将目标文件换为一个不存在的文件时报错
>>> 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)
复制所有的状态信息，包括权限，组，用户，时间等
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)
复制文件的内容以及权限，先copyfile后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)
复制文件的内容以及文件的所有状态信息。先copyfile后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)
递归的复制文件内容及状态信息
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)
递归地删除文件
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)
递归的移动文件
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)
压缩打包
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： 压缩打包后的文件名或者路径名
format： 压缩或者打包格式 "zip", "tar", "bztar"or "gztar"
root_dir : 将哪个目录或者文件打包（也就是源文件）
>>> 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
