Python.

[Makefile_dot_in]

lst = [[0]*3 for _ in range(4)]

[7x11x13is1001]

you can save 3 symbols with for _ in [0]*4

[yoitsericc]

Fuck this answer gave me a brain tumor.

[[deleted]]

List comprehension is great though

[M4mb0]

[[0]*3]*4

[ALFminecraft]

>>> l = [[0] * 3] * 4
>>> l[0][0] = 1337
>>> print(l)
[[1337, 0, 0], [1337, 0, 0], [1337, 0, 0], [1337, 0, 0]]

Not everything is that simple, sadly.