Is it a way to capture text as 'internal variables' in regex?

So i have these string test1string2 , test2string2 and test3string3.

Regex "test/dstring/d" would capture the three of them, but is there a way to write a regex that will capture only the second and third strings? Sort of: capture "test" followed by any number followed by "string" followed by a number but only if those numbers are the same.

I am working in python if it adds relevant info

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>Solution :

You are looking for backreference in python‘s re it is backslash followed by number of capturing group, consider following simple example

import re
texts = ['A1A1','A1B2','A1C1']
for t in texts:
    if re.match(r'[A-Z](\d)[A-Z]\1',t):
        print(t)

gives output

A1A1
A1C1