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

This approach avoids the warnings while preserving the array-oriented evaluation.

import numpy as np
def isnat(x):
    """ 
    datetime64 analog to isnan.
    doesn't yet exist in numpy - other ways give warnings
    and are likely to change.  
    """
    return x.astype('i8') == np.datetime64('NaT').astype('i8')