Efficiently initialize 2D array of size n*m in Python 3?

Question

I am using Python 3 and am trying to create 2D integer arrays of a known and fixed size. How can I do this?

The arrays I have in mind are the Python-provided array.array, although I am not averse to using a library like NumPy.

I know this can be done via lists, but I want to use an array since they are much more space efficient. Right now, I am initializing lists in this way, but I want to replace it with an array:

my_list = [[ 0 for _ in range(height) ] for _ in range(.width)]

For example, in C, I would write

int my_array[ width ][ height ];

How can I do this in Python

Answer 1

You can use numpy:

import numpy as np
my_array = np.zeros([height, width])

For example:

>>> np.zeros([3, 5])
array([[ 0.,  0.,  0.,  0.,  0.],
       [ 0.,  0.,  0.,  0.,  0.],
       [ 0.,  0.,  0.,  0.,  0.]])

Note that if you specifically need integers, you should use the dtype argument

>>> np.zeros([3, 5], dtype=int)
array([[0, 0, 0, 0, 0],
       [0, 0, 0, 0, 0],
       [0, 0, 0, 0, 0]])