code: def search(self, string, pos=0, endpos=sys.maxint):
          
          state = _State(string, pos, endpos, self.flags)
          if state.search(self._code):
              return SRE_Match(self, state)
          else:
              return None
docs: Scan through string looking for a location where this regular
          expression produces a match, and return a corresponding MatchObject
          instance. Return None if no position in the string matches the
          pattern.