在一个目录中运行以下代码，该目录包含一个名为bar的目录(包含一个或多个文件)和一个名为baz的目录(也包含一个或多个文件)。确保没有名为foo的目录。
import shutil
shutil.copytree('bar', 'foo')
shutil.copytree('baz', 'foo')
它将失败:
$ python copytree_test.py
Traceback (most recent call last):
File "copytree_test.py", line 5, in <module>
shutil.copytree('baz', 'foo')
File "/System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/shutil.py", line 110, in copytree
File "/System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/os.py", line 172, in makedirs
OSError: [Errno 17] File exists: 'foo'
我想让它像我输入的那样工作:
$ mkdir foo
$ cp bar/* foo/
$ cp baz/* foo/
我需要使用shutil.copy()复制每个文件在baz到foo?(在我已经用shutil.copytree()将'bar'的内容复制到'foo'后?)或者有更简单/更好的方法吗?
这是我对这个问题的看法。我修改了copytree的源代码以保持原来的功能，但是现在当目录已经存在时不会发生错误。我还修改了它，这样它就不会覆盖现有的文件，而是保留两个副本，其中一个具有修改后的名称，因为这对我的应用程序很重要。
import shutil
import os
def _copytree(src, dst, symlinks=False, ignore=None):
"""
This is an improved version of shutil.copytree which allows writing to
existing folders and does not overwrite existing files but instead appends
a ~1 to the file name and adds it to the destination path.
"""
names = os.listdir(src)
if ignore is not None:
ignored_names = ignore(src, names)
else:
ignored_names = set()
if not os.path.exists(dst):
os.makedirs(dst)
shutil.copystat(src, dst)
errors = []
for name in names:
if name in ignored_names:
continue
srcname = os.path.join(src, name)
dstname = os.path.join(dst, name)
i = 1
while os.path.exists(dstname) and not os.path.isdir(dstname):
parts = name.split('.')
file_name = ''
file_extension = parts[-1]
# make a new file name inserting ~1 between name and extension
for j in range(len(parts)-1):
file_name += parts[j]
if j < len(parts)-2:
file_name += '.'
suffix = file_name + '~' + str(i) + '.' + file_extension
dstname = os.path.join(dst, suffix)
i+=1
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:
shutil.copy2(srcname, dstname)
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 BaseException as err:
errors.extend(err.args[0])
try:
shutil.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 BaseException(errors)
这是受到atzz提供的原始最佳答案的启发，我只是添加了替换文件/文件夹逻辑。所以它实际上并没有合并，而是删除现有的文件/文件夹并复制新的文件/文件夹:
import shutil
import os
def copytree(src, dst, symlinks=False, ignore=None):
for item in os.listdir(src):
s = os.path.join(src, item)
d = os.path.join(dst, item)
if os.path.exists(d):
try:
shutil.rmtree(d)
except Exception as e:
print e
os.unlink(d)
if os.path.isdir(s):
shutil.copytree(s, d, symlinks, ignore)
else:
shutil.copy2(s, d)
#shutil.rmtree(src)
取消注释rmtree，使其成为一个move函数。
这是我对这个问题的看法。我修改了copytree的源代码以保持原来的功能，但是现在当目录已经存在时不会发生错误。我还修改了它，这样它就不会覆盖现有的文件，而是保留两个副本，其中一个具有修改后的名称，因为这对我的应用程序很重要。
import shutil
import os
def _copytree(src, dst, symlinks=False, ignore=None):
"""
This is an improved version of shutil.copytree which allows writing to
existing folders and does not overwrite existing files but instead appends
a ~1 to the file name and adds it to the destination path.
"""
names = os.listdir(src)
if ignore is not None:
ignored_names = ignore(src, names)
else:
ignored_names = set()
if not os.path.exists(dst):
os.makedirs(dst)
shutil.copystat(src, dst)
errors = []
for name in names:
if name in ignored_names:
continue
srcname = os.path.join(src, name)
dstname = os.path.join(dst, name)
i = 1
while os.path.exists(dstname) and not os.path.isdir(dstname):
parts = name.split('.')
file_name = ''
file_extension = parts[-1]
# make a new file name inserting ~1 between name and extension
for j in range(len(parts)-1):
file_name += parts[j]
if j < len(parts)-2:
file_name += '.'
suffix = file_name + '~' + str(i) + '.' + file_extension
dstname = os.path.join(dst, suffix)
i+=1
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:
shutil.copy2(srcname, dstname)
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 BaseException as err:
errors.extend(err.args[0])
try:
shutil.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 BaseException(errors)
