RegExp match repeated characters

Question

For example I have string:

 aacbbbqq

As the result I want to have following matches:

 (aa, c, bbb, qq)  

Answer 1

Generally

The trick is to match a single char of the range you want, and then make sure you match all repetitions of the same character:

>>> matcher= re.compile(r'(.)\1*')

This matches any single character (.) and then its repetitions (\1*) if any.

For your input string, you can get the desired output as:

>>> [match.group() for match in matcher.finditer('aacbbbqq')]
['aa', 'c', 'bbb', 'qq']

NB: because of the match group, re.findall won't work correctly.

Other ranges

In case you don't want to match any character, change accordingly the . in the regular expression:

>>> matcher= re.compile(r'([a-z])\1*') # only lower case ASCII letters
>>> matcher= re.compile(r'(?i)([a-z])\1*') # only ASCII letters
>>> matcher= re.compile(r'(\w)\1*') # ASCII letters or digits or underscores
>>> matcher= re.compile(r'(?u)(\w)\1*') # against unicode values, any letter or digit known to Unicode, or underscore

Check the latter against u'hello²²' (Python 2.x) or 'hello²²' (Python 3.x):

>>> text= u'hello=\xb2\xb2'
>>> print('\n'.join(match.group() for match in matcher.finditer(text)))
h
e
ll
o
²²

\w against non-Unicode strings / bytearrays might be modified if you first have issued a locale.setlocale call.