python create matrix of size n code example

Example 1: python create n*n matrix

# Creates a list containing 5 lists, each of 8 items, all set to 0
w, h = 8, 5;
Matrix = [[0 for x in range(w)] for y in range(h)]

Example 2: size of matrix python

>>> a=[[1,5,6,8],[1,2,5,9],[7,5,6,2]]
>>> len(a)
3
>>> len(a[0])
4