Python regex- Find the longest repeated substring using findall()?

Question

This returns 'hhhhhhh' which is what I want

max(re.findall('h+', 'hhhhhhhahahahahahaaaaa'), key = len)

but this only returns a single 'ha'?

max(re.findall('(ha)+', 'hhhhhhhahahahahahaaaaa'), key = len)

How do I make it return 'hahahahaha'?

Answer 1

You'd need to put a non-capturing group around the part that you want to repeat. Then the outermost group should be used by default, as in the first example with h+ .

import re

res = max(re.findall('(?:ha)+', 'hhhhhhhahahahahahaaaaa'), key = len)
print(res)

Prints:

hahahahahaha