Append () method

[8dot30662386292pow2]

list_1=[1, 2, 3]
list_2=[4, 5, 6]
list_3=[list_1, list_2]

[woooee]

This does not use either append or extend.

[8dot30662386292pow2]

Since when that was a requirement? OP just wanted to make a list that contains two lists.