How to count number of zeros in Numpy array?

Let’s check how many zeros there are in your array. We will use the Numpy count_nonzero function.

Numpy count number of zeros

Using count_nonzero method

To check how many zeros you have in your array you need to know count_nonzero function.

Just put my_array==0 as an argument as in below example.

import numpy as np

my_array = np.array([0, 7, 6, 5,
                     0, 0, 0, 7,
                     0, 3, 2, 0])

zeros = np.count_nonzero(my_array == 0)

print(f"There are {zeros} zeros in my array.")

Numpy count number of zeros

As you can see, Python printed out the number of zeros from the array.

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Using where method

Another way to count the number of zeros in an array is to use the Numpy where method.


import numpy as np

my_array = np.array([0, 7, 6, 5,
                     0, 0, 0, 7,
                     0, 3, 2, 0])

zeros = my_array[np.where(my_array == 0)]

print(f"There are {zeros.size} zeros in my array.")

Thanks to Numpy where function, it is possible to create additional zeros array which contains only zeros. The answer would be the size of zeros array.

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The output would be:

There are 6 zeros in my array.