array

 1def test():
 2    data1 = [1, 2, 3]
 3    data2 = ["a", "b", "c"]
 4
 5    data1.append(4)
 6    data1.extend(data2)
 7
 8    print(len(data1), data1)
 9
10
11def main():
12    test()
13
14
15if __name__ == "__main__":
16    main()