How to find NaN in NumPy array

You can find NaN in the NumPy array with the following code. If you want to learn Python then I will highly recommend you to read This Book.

How to check is there any NaN in NumPy array?

import numpy as np
a = np.array([1, 2, 3, np.nan, 5, np.nan])
print(np.isnan(a))
# Output is [False False False  True False  True]

import numpy as np
a = np.array([1, 2, 3, np.nan, 5, np.nan])
print(np.argwhere(np.isnan(a)))
# Output is 
[[3]
 [5]]

import numpy as np
a = np.array([1, 2, 3, np.nan, 5, np.nan])
print(np.count_nonzero(np.isnan(a)))
# Output is 2

import numpy as np
a = np.array([1, 2, 3, np.nan, 5, np.nan])
print(np.count_nonzero(~np.isnan(a)))
# Output is 4