EX_re_groups_nested.py

"""~/Python $ python re_groups_nested.py
Pattern 'a((a*)(b*))' (a followed by 0-n a and 0-n b)

 'abbaabbba'
Traceback (most recent call last):
  File "re_groups_nested.py", line 8, in <module>
    [(r'a((a*)(b*))', 'a followed by 0-n a and 0-n b'),
  File "/home/rfmonk/Python/re_test_patterns2.py", line 19, in test_patterns
    print ' %s%r' % (prefix, text[s:e], ' ' * (len(text) - e)),
TypeError: not all arguments converted during string formatting
"""