redis cmd to bulk

def cmd2bulk(*cmd):
    z = lambda x: ((lambda y=bytes(str(x), "utf-8"): len(y))(), x)
    return "*%d\r\n%s" % (len(cmd), "".join(["$%d\r\n%s\r\n" % z(x) for x in cmd]))

if __name__ == '__main__':
    import sys
    import unittest

    class TestRedisBulk(unittest.TestCase):

        def test_redis_proto1(self):
            expect = "*3\r\n$3\r\nSET\r\n$6\r\nKEY985\r\n$8\r\nVALUE985\r\n"
            result = cmd2bulk("SET", "KEY985", "VALUE985")
            self.assertEqual(expect, result)

        def test_redis_proto2(self):
            expect = "*5\r\n$4\r\nSADD\r\n$4\r\nhoge\r\n$9\r\nあああ\r\n$6\r\nいい\r\n$3\r\nう\r\n"
            result = cmd2bulk("SADD", "hoge", "あああ", "いい", "う")
            self.assertEqual(expect, result)

    unittest.main()