code: def matches(self, s, parseAll=True):
          
          try:
              self.parseString(_ustr(s), parseAll=parseAll)
              return True
          except ParseBaseException:
              return False
docs: Method for quick testing of a parser against a test string. Good for simple 
             inline microtests of sub expressions while building up larger parser, as in:
             
             expr = Word(nums)
             assert expr.matches("100")
             
             Parameters:
              - testString - string