i have a matrix

Matrix = [[[]] * 5 for i in range(5)]

i'm trying to change the inner element with the following code, but somewhy it changes the whole row instead:

Matrix[0][1].append(1)

output:

[[[1], [1], [1], [1], [1]], [[], [], [], [], []], [[], [], [], [], []], [[], [], [], [], []], [[], [], [], [], []]]

but i wanted it to work like this:

[[[], [1], [], [], []], [[], [], [], [], []], [[], [], [], [], []], [[], [], [], [], []], [[], [], [], [], []]]

CodePudding user response：

You want to use loops inside and outside the list of lists to avoid creating copies.

Matrix = [[[] for _ in range(5)] for i in range(5)]

print(Matrix)
[[[], [1], [], [], []], [[], [], [], [], []], [[], [], [], [], []], [[], [], [], [], []], [[], [], [], [], []]]