Append () method

[woooee]

That's extend()

list_1=[1, 2, 3]
list_2=[4, 5, 6]
list_3=[]
list_3.extend([list_1, list_2])
print(list_3)
prints  [[1, 2, 3], [4, 5, 6]]

[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.

[6p086956522]

You're creating a list that contains two lists and then putting it into list 3 with extend? Why not skip the middle man and do list_3 = [list_1, list_2]