Python re.sub to replace 3 or more of same character with 1

Question

I\'m trying to find characters that are repeated 3 times or more, for example I want to take the following strings:

(\'aaa\', \'buuuuut\',

Answer 1

>>> s = 'abbcccffffdd'
>>> s = re.sub(r'(\w)\1(\1+)',r'\1',s)
>>> s
'abbcd'