Suppose you want to create an array with 4 rows and 3 columns.
Way 1
cols = 3
rows = 4
table = [[0] * cols for _ in range(rows)]
this code will give you:
[[0, 0, 0], [0, 0, 0], [0, 0, 0], [0, 0, 0]]
Do not use the following code, this is a pitfall, never!
table = [[0] * cols ] * rows
Because, when you change one of the elements, say table[1][1], set it to 1, 4 elements will be changed at the same time!
In [41]: table = [[0] * cols ] * rows
...:
In [42]: table
Out[42]: [[0, 0, 0], [0, 0, 0], [0, 0, 0], [0, 0, 0]]
In [43]: table[1][1] = 1
In [44]: table
Out[44]: [[0, 1, 0], [0, 1, 0], [0, 1, 0], [0, 1, 0]]
Way 2
Using numpy package.
In [1]: import numpy as np
In [4]: np.zeros([4,3])
Out[4]:
array([[0., 0., 0.],
[0., 0., 0.],
[0., 0., 0.],
[0., 0., 0.]])