在另一个字符串中匹配子字符串

Question

I have two lists that contain strings. The first list contains a list of files and directories:

list1 = ['path/to/my/files',
         'path/to/more/of/my/files',
         'path/to/my/dirs',
         'path/to/more/of/mydirs']

The second list contains dirs that I want to check against list1 for existence.

list2 = ['path/to/my',
         'random/path/to/somewhere',
         'path/does/not/matter',
         'hey/path/is/here']

The only results I want is path/to/my/* , but when I use str.find() it is returning any string that contains path or to or my regardless of where it occurs in the string.

So instead of just getting:

path/to/my/files
path/to/my/dirs

I get everything in list1

My code is like so:

for dir in list2:
   for path in list1:
      if path.find(dir):
         print(path)

Answer 1

All non-zero numbers are Truthy. When your string is not found, .find() returns -1 which is still True . You need to make sure the result is not -1 :

for dir in list2:
    for path in list1:
        if path.find(dir) != -1:
            print(path)

As @PadraicCunningham mentioned in a comment, that isn't the easiest way. Just use the in operator:

for dir in list2:
    for path in list1:
        if dir in path:
            print(path)

Answer 2

我认为您需要的是str.startswith()