How to copy the elements of the list within the list?

I have a list list_1 = [[1,2,3], [4,5,6], [7,8,9], ....]. I want [[1,2,3], [1,2,3], [4,5,6], [4,5,6], [7,8,9], [7,8,9]]. How can i achieve this?
Its like basically copying each element of the list to its consecutive index.

>Solution :

from copy import deepcopy

def multiply_list_elem(lst, n):
    out = list()
    for elem in lst:
        for _ in range(n):
            out.append(deepcopy(elem))
    return out

if __name__ == '__main__':
    list_1 = [[1,2,3], [4,5,6], [7,8,9]]
    print(multiply_list_elem(list_1, 2))