user input for multi-dimentional list without a prior iteration using input()

[Larz60+]

what you have is a double cast, which is the same as a single cast.
that's like saying red, red is the barn colour
and thus both will give you a single dimension list

example:

>>> l = list(list(input().split()))
1 2 3 4 5
>>> l
['1', '2', '3', '4', '5']
>>> l = list(input().split())
1 2 3 4 5
>>> l
['1', '2', '3', '4', '5']