:example '4703'

def postcode_in_state(self, state_abbr=None):
        """
        :example '4703'
        """
        if state_abbr is None:
            state_abbr = self.random_element(self.states_abbr)

        if state_abbr in self.states_abbr:
            postcode = "%d" % (self.generator.random.randint(
                            self.states_postcode[state_abbr][0],
                            self.states_postcode[state_abbr][1]))

            if len(postcode) == 3:
                postcode = "0%s" % postcode

            return postcode

        else:
            raise Exception('State Abbreviation not found in list')