How to use re.sub to match and substitute any numbers after – extension?

October 3, 2022

I want to substitute from ‘datasets/4/image-3.jpg’ to ‘datasets/4/image-1.jpg’. Are there any ways to do it by using re.sub? Or should I try something else like .split("/")[-1]? I had tried below but end up getting ‘datasets/1/image-1.jpg’, but I want to keep the /4/ instead of /1/.

My Code

import re
employee_name = 'datasets/4/image-3.jpg'
label = re.sub('[0-9]', "1", employee_name)
print(label)

Output

datasets/1/image-1.jpg

Expected Input

datasets/4/image-3.jpg

Expected Output

datasets/4/image-1.jpg

>Solution :

You can use

re.sub(r'-\d+\.jpg', '-1.jpg', text)

Note: If the match is always at the end of string, append the $ anchor at the end of the regex. If there can be other text after and you need to make sure there are no word chars after jpg, add a word boundary, \b. If you want to match other extensions, use a group, e.g. (?:jpe?g|png).

Regex details