string1 = """
              one
              two
              3
              """
string2 = """
              one
              ttttttt
              3 
              """

#!/usr/bin/env python
#-*- coding: utf8 -*-
import difflib
string1 = """
          one
          two
          3
          """.splitlines()
string2 = """
          one
          ttttttt
          3
          """.splitlines()
diff = list(difflib.ndiff(string1, string2))
print '\n'.join(difflib.restore(diff, 2))