问题描述
在 python 2.7 中的 Mac 上，使用 os.walk 遍历目录时，我的脚本会遍历apps"，即 appname.app，因为这些实际上只是它们自己的目录.后来在处理过程中，我在处理它们时遇到了错误.我无论如何都不想浏览它们，因此就我的目的而言，最好忽略这些类型的目录".
On a mac in python 2.7 when walking through directories using os.walk my script goes through 'apps' i.e. appname.app, since those are really just directories of themselves. Well later on in processing I am hitting errors when going through them. I don't want to go through them anyways so for my purposes it would be best just to ignore those types of 'directories'.
这是我目前的解决方案:
So this is my current solution:
for root, subdirs, files in os.walk(directory, True):
for subdir in subdirs:
if '.' in subdir:
subdirs.remove(subdir)
#do more stuff
如您所见，第二个 for 循环将针对子目录的每次迭代运行，这是不必要的，因为第一遍删除了我想要删除的所有内容.
As you can see, the second for loop will run for every iteration of subdirs, which is unnecessary since the first pass removes everything I want to remove anyways.
必须有更有效的方法来做到这一点.有什么想法吗?
There must be a more efficient way to do this. Any ideas?
推荐答案
你可以这样做(假设你想忽略包含 '.' 的目录):
You can do something like this (assuming you want to ignore directories containing '.'):
subdirs[:] = [d for d in subdirs if '.' not in d]
切片分配(而不仅仅是 subdirs = ...)是必要的，因为您需要修改 os.walk 正在使用的相同列表，而不是创建一个新的.
The slice assignment (rather than just subdirs = ...) is necessary because you need to modify the same list that os.walk is using, not create a new one.
请注意，您的原始代码不正确，因为您在迭代列表时修改了列表，这是不允许的.
Note that your original code is incorrect because you modify the list while iterating over it, which is not allowed.
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