Python列表索引

Question

I have a dual list and I am wondering what it the best way to get the indexes of the zeros in the array

board =[[1,2,0],
    [2,1,2],
    [1,1,0]]

for boxes in board:
    if 0 in boxes:
        print boxes

like this but instead I want to have return [0,2] [2,2]

Answer 1

Your question is very vague (what about multiple zeroes in one of the inner lists), feel free to comment if you are looking for something else:

zeroes = []
for x, box in enumerate(board):
    if 0 in box:
        zeroes.append((x, box.index(0)))
print zeroes

With your given lists, this prints

[(0, 2), (2, 2)]

A shorter, more pythonic version would be using a list comprehension like this:

zeroes = [(x, box.index(0)) for x, box in enumerate(board) if 0 in box]

Answer 2

You could use a list comprehension:

[(i, j) for i in range(3) for j in range(3) if board[i][j] == 0]

This will include multiple zeros per row if present.