board_1 = [[0]*4]*4
board_2 = [[0,0,0,0], [0,0,0,0], [0,0,0,0], [0,0,0,0]]
both the above methods yield the following list.
[[0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0]]
but when we replace an element(3,3) in those list we get different result
board_1[3][3] = 1
this will yield
[[0, 0, 0, 1], [0, 0, 0, 1], [0, 0, 0, 1], [0, 0, 0, 1]]
whereas, the below will get the correct output
board_2[3][3] = 1
[[0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 1]]
why we get two different result?
