How can I declare a 5x5 grid of numbers in Python?

Question

How would I declare this? I'm thinking something along the lines of:

boardPieces = ["A","O","A"
               "A", "A", "O"
              ]

Answer 1

[[0] * 5 for x in range(5)]

or

[[0 for x in range(5)] for y in range(5)]

The first will only work with immutable types, while the second will work with any type.

Answer 2

I'm assuming a 2d matrix? Something like this should work.

boardPieces = [["A","O","A","A", "A"],["A","O","A","A", "A"],["A","O","A","A", "A"],["A","O","A","A", "A"],["A","O","A","A", "A"]]

Answer 3

Just do like this.

[["A","O","A","O","A"],[...],[...],[...],[...]]

Answer 4

In addition to the answers given - if you need to do work with 2D (or higher dimension) arrays in Python, a very good library for this purpose is Numpy - http://numpy.scipy.org/.

Among others, it lets you easily "reshape" an array in whatever logical form fits you at a particular moment (for example, an list of 6 values can be treated as any of the following arrays - 1x6, 2x3, 3x2, ...).

The output of this code -

import numpy

boardPieces = numpy.array( [ "A", "O", "A", "A", "A", "O" ], numpy.character )
boardPieces = boardPieces.reshape( [ 2, 3 ] )
print boardPieces
boardPieces = boardPieces.reshape( [ 3, 2 ] )
print boardPieces

Would be -

[['A' 'O' 'A']
 ['A' 'A' 'O']]
[['A' 'O']
 ['A' 'A']
 ['A' 'O']]

Might not be suitable for your particular use-case, but can serve as a reference for others.