How do I copy a list as described under?

Question

I am writing a code in python. This code requires copying a nested list A in B. But when I make changes to the list members of B, these are made to A as well. This problem arises due to the alias effect.

Answer 1

Make a shallow copy of the list. If that doesn't work make a deep copy.

lst = [[1, 2], [3, 4]]

new_list = lst[0]
shallow_copy = lst[0][:]

lst[0][0] = 42
print(new_list) # [42, 2]
print(shallow_copy) # [1, 2]

Answer 2

Sorry but shallow copy did not work.

But I was able to complete the code by using deepcopy function from copy module.

Answer 3

Sorry but shallow copy did not work.

But I was able to complete the code by using deepcopy function from copy module.