python里使用正则表达式的组嵌套实例详解

#python 3.6 
#蔡军生  
#http://blog.csdn.net/caimouse/article/details/51749579 
# 
import re 
 
 
def test_patterns(text, patterns): 
  """Given source text and a list of patterns, look for 
  matches for each pattern within the text and print 
  them to stdout. 
  """ 
  # Look for each pattern in the text and print the results 
  for pattern, desc in patterns: 
    print('{!r} ({})\n'.format(pattern, desc)) 
    print(' {!r}'.format(text)) 
    for match in re.finditer(pattern, text): 
      s = match.start() 
      e = match.end() 
      prefix = ' ' * (s) 
      print( 
        ' {}{!r}{} '.format(prefix, 
                   text[s:e], 
                   ' ' * (len(text) - e)), 
        end=' ', 
      ) 
      print(match.groups()) 
      if match.groupdict(): 
        print('{}{}'.format( 
          ' ' * (len(text) - s), 
          match.groupdict()), 
        ) 
    print() 
  return 

#python 3.6 
#蔡军生  
#http://blog.csdn.net/caimouse/article/details/51749579 
# 
from re_test_patterns_groups import test_patterns 
 
test_patterns( 
  'abbaabbba', 
  [(r'a((a*)(b*))', 'a followed by 0-n a and 0-n b')], 
) 

'a((a*)(b*))' (a followed by 0-n a and 0-n b)


 'abbaabbba'
 'abb'    ('bb', '', 'bb')
   'aabbb'  ('abbb', 'a', 'bbb')
     'a' ('', '', '')