Search code examples
pythonarraysmultidimensional-arraypseudocode

How to initialise a 2D array in Python?


I've been given the pseudo-code:

    for i= 1 to 3
        for j = 1 to 3
            board [i] [j] = 0
        next j
    next i

How would I create this in python?

(The idea is to create a 3 by 3 array with all of the elements set to 0 using a for loop).


Solution

  • If you really want to use for-loops:

    >>> board = []
    >>> for i in range(3):
    ...     board.append([])
    ...     for j in range(3):
    ...         board[i].append(0)
    ... 
    >>> board
    [[0, 0, 0], [0, 0, 0], [0, 0, 0]]
    

    But Python makes this easier for you:

    >>> board = [[0]*3 for _ in range(3)]
    >>> board
    [[0, 0, 0], [0, 0, 0], [0, 0, 0]]