Assigning value in python 2d list

Question

I have previously worked in C, I am facing problem in assigning value in 2d list

graph = [[0]*3]*3
print(graph)
graph[0][1] = 3
print(graph)

Output

[[0, 0, 0], [0, 0, 0], [0, 0, 0]]
[[0, 3, 0], [0, 3, 0], [0, 3, 0]]

Expected output :

[[0, 3, 0], [0, 0, 0], [0, 0, 0]]

Is there any way to assign values other than using numpy array as answered in Assigning values Python 2D Array

It's a recurrent question. Try `graph = [[0 for _ in range(3)] for _ in range(3)]` instead when you make `graph`. — j1-lee, Mar 02 '22 at 06:15
Yes, but I still can't understand how is it different from graph = [[0]*3]*3 — Amish, Mar 02 '22 at 06:17

score 2 · Answer 1 · answered Mar 02 '22 at 06:15

2

you can use a for loop to do this simply

a = []
for i in range(3):
    a.append([0]*3)

answered Mar 02 '22 at 06:15

1 Answers1