0

我编写了一个函数来递归地将文件从目录 A 复制到目录 B。代码是这样的：

import os
import shutil
import sys
from os.path import join, exists

def copy_file(src, dest):
    for path, dirs, files in os.walk(src, topdown=True):
        if len(dirs) > 0:
            for di in dirs:
                copy_file(join(path, di), join(dest,  di))

        if not exists(dest):
            os.makedirs(dest)
        for fi in files:
            shutil.copy(join(path, fi), dest)

在我的测试中，输入参数是这样的：

src = d:/dev

它有一个名为py. 此外，py有一个名为的子目录test

dest = d:/dev_bak

所以，当我测试我的代码时，发生了一些奇怪的事情。在我的dest目录中d:/dev_bak，创建了三个子目录。即：d:/dev_bak/py; d:/dev_bak/py/test; d:/dev_bak/test.

在我的设计中， 的结构dev_bak将与dev. 那么，为什么会这样！

4

2 回答 2

2

您可以通过放置轻松诊断此问题

    print path, dirs, files

正下方

for path, dirs, files in os.walk(src, topdown=True):

本质上，你递归两次。

本身，os.walk下降到子目录。您通过递归调用自己的函数来进行双降。以下是该print语句的一些示例输出：

>>> copy_file("c:\Intel", "c:\Intel-Bak")
c:\Intel ['ExtremeGraphics', 'Logs'] []
c:\Intel\ExtremeGraphics ['CUI'] []
c:\Intel\ExtremeGraphics\CUI ['资源'] []
c:\Intel\ExtremeGraphics\CUI\Resource [] ['Intel\xae Graphics and Media Control Panel.lnk', 'Intel\xae HD Graphics.lnk']
c:\Intel\ExtremeGraphics\CUI\Resource [] ['Intel\xae Graphics and Media Control Panel.lnk', 'Intel\xae HD Graphics.lnk']
c:\Intel\ExtremeGraphics\CUI ['资源'] []
c:\Intel\ExtremeGraphics\CUI\Resource [] ['Intel\xae Graphics and Media Control Panel.lnk', 'Intel\xae HD Graphics.lnk']
c:\Intel\ExtremeGraphics\CUI\Resource [] ['Intel\xae Graphics and Media Control Panel.lnk', 'Intel\xae HD Graphics.lnk']
c:\Intel\Logs [] ['IntelChipset.log', 'IntelControlCenter.log', 'IntelGFX.log', 'IntelGFXCoin.log']
c:\Intel\ExtremeGraphics ['CUI'] []
c:\Intel\ExtremeGraphics\CUI ['资源'] []
c:\Intel\ExtremeGraphics\CUI\Resource [] ['Intel\xae Graphics and Media Control Panel.lnk', 'Intel\xae HD Graphics.lnk']
c:\Intel\ExtremeGraphics\CUI\Resource [] ['Intel\xae Graphics and Media Control Panel.lnk', 'Intel\xae HD Graphics.lnk']
c:\Intel\ExtremeGraphics\CUI ['资源'] []
c:\Intel\ExtremeGraphics\CUI\Resource [] ['Intel\xae Graphics and Media Control Panel.lnk', 'Intel\xae HD Graphics.lnk']
c:\Intel\ExtremeGraphics\CUI\Resource [] ['Intel\xae Graphics and Media Control Panel.lnk', 'Intel\xae HD Graphics.lnk']
c:\Intel\Logs [] ['IntelChipset.log', 'IntelControlCenter.log', 'IntelGFX.log', 'IntelGFXCoin.log']

如您所见，目录被访问了两次。

您应该修复程序的逻辑，使其仅访问每个目录一次，但理论上您可以忽略您已经访问过的任何目录：

visited = []
def copy_file(src, dest):
    for path, dirs, files in os.walk(src, topdown=True):
        if path not in visited:
            for di in dirs:
                print dest, di
                copy_file(join(path, di), join(dest,  di))
            if not exists(dest):
                os.makedirs(dest)
            for fi in files:
                shutil.copy(join(path, fi), dest)
            visited.append(path)
于 2012-04-11T17:00:19.627 回答
0

shutil模块已经有一个copytree函数，它将递归地复制目录。您可能想要使用它而不是提供自己的实现。

于 2012-04-11T16:54:16.827 回答