.*? 不理解

#!/usr/bin/python

import re

line = "Cats are smarter than dogs"

matchObj = re.match( r'(.*) are (.*?) .*', line, re.M|re.I)

if matchObj:   

   print "matchObj.group() : ", matchObj.group()

   print "matchObj.group(1) : ", matchObj.group(1)

   print "matchObj.group(2) : ", matchObj.group(2)

else:

   print "No match!!"

运行成功

matchObj.group() :  Cats are smarter than dogs
matchObj.group(1) :  Cats
matchObj.group(2) :  smarter