Python re.findall() is not working as expected

Question

I have the code:

import re
sequence=\"aabbaa\"
rexp=re.compile(\"(aa|bb)+\")
rexp.findall(sequence)

This returns [\'aa\']

Answer 1

I do not understand why you use + - it means 0 or 1 occurrence, and is usually used when you want find string with optional inclusion of substring.

>>> re.findall(r'(aa|bb)', 'aabbaa')
['aa', 'bb', 'aa']

work as expected