Numpy: Checking if a value is NaT

Question

nat = np.datetime64(\'NaT\')
nat == nat
>> FutureWarning: In the future, \'NAT == x\' and \'x == NAT\' will always be False.

np.isnan(nat)
>> TypeError:         


        

Answer 1

Since NumPy version 1.13 it contains an isnat function:

>>> import numpy as np
>>> np.isnat(np.datetime64('nat'))
True

It also works for arrays:

>>> np.isnat(np.array(['nat', 1, 2, 3, 4, 'nat', 5], dtype='datetime64[D]'))
array([ True, False, False, False, False,  True, False], dtype=bool)