Make numpy matrix more sparse

Question

Suppose I have a numpy array

np.array([
    [3, 0, 5, 3, 0, 1],
    [0, 1, 2, 1, 5, 2],
    [4, 3, 5, 3, 1, 4],
    [2, 5, 2, 5, 3, 1],
    [0, 1, 2, 1, 5, 2],
]         


        

Answer 1

Use np.ravel or the ravel method to create a flattened. Note that the flatten method always creates a copy, so mutating won't work.

a = np.array([
    [3, 0, 5, 3, 0, 1],
    [0, 1, 2, 1, 5, 2],
    [4, 3, 5, 3, 1, 4],
    [2, 5, 2, 5, 3, 1],
    [0, 1, 2, 1, 5, 2],
])
r = a.ravel()
r[random.randrange(0, len(r))] = 0