不区分大小写的文件名模式匹配返回 None

Question

Update: How do I return a string from a regex match in python? - this question seems similar and I've updated accordingly.

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I'm trying to open a file to write to it but, I don't know its case, so I'm trying to case-insensitive match its filename from its path.

Currently, with print(my_file) , I see all the files in the folder_path but, file_match returns None. I also tried re.search instead of re.match and it returns None as well.

import re
from pathlib import Path as p
cwd = p.cwd()

folder_path = p(cwd / 'somefolder')

for my_file in folder_path.iterdir():
    print(my_file)
    file_match = re.search('.+/test.txt', str(my_file), re.IGNORECASE)
    print(file_match) # Gives me <re.Match object; span=(0, 97), match='/the/path>

print(file_match) # gives me None

I'm hoping to match one of the following etc:

• /cwd/somefolder/test.txt
• /cwd/somefolder/TEst.Txt
• /cwd/SOMEFolder/teSt.TXT

but not this:

• /cwd/somefolder/NotTest.txt
• /cwd/somefolder/Other.mp3

Ultimately, I want a variable that includes the path to the /cwd/somefolder/test.txt, just in any case it happens to exist in. This way I can open and write to said file.

Here's the regular expression I'm using, which appears to be working: https://regex101.com/r/hz5qNe/2

Note: there is only one test.txt in each folder I'm searching in but, I don't know its case ie the filename is always the same but, the case can be different depending on the current folder_path iteration (I'm looping to find each folder's test.txt path but, didn't include that in the above code, as to par it down to its simplest form.)

Any help would be appreciated, thanks!

Answer 1

I would suggest dropping re and use the following test:

if my_file.name.lower() == 'test.txt':
    ...

This should make the code also easier to understand and maintain.

If you then need to access the folder name you can just use the my_file.parent property.

Answer 2

You need to pull it out of the regex Match Object using .group(), like this demo - ( source )

import re
from pathlib import Path as p
cwd = p.cwd()

folder_path = p(cwd / 'somefolder')

for my_file in folder_path.iterdir():
     file_match = re.search('.+/test.txt', str(my_file), re.IGNORECASE)
     if file_match:
         match = file_match.group()

print(match) # prints: /cwd/somefolder/test.txt (or any case of test.txt, which ever case is present...)