Return python code for create and execute machine.

def compile(self):
        """Return python code for create and execute machine."""
        result = TEMPLATE
        result += 'machine = Machine(' + repr(self.alphabet) + ')\n'

        for state in self.states:
            repr_state = state[0]
            for rule in self.states[state]:
                repr_state += ' ' + (','.join(rule) if rule is not None else '-')

            result += ("machine.add_state({repr_state})\n".format(repr_state=repr(repr_state)))

        result += "for line in stdin:\n"
        result += "    print(machine.execute(line))"
        return result