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

Very simple and surprisingly fast: (without numpy or pandas)

    str( myDate ) == 'NaT'            # True if myDate is NaT

Ok, it's a little nasty, but given the ambiguity surrounding 'NaT' it does the job nicely.

It's also useful when comparing two dates either of which might be NaT as follows:

   str( date1 ) == str( date1 )       # True
   str( date1 ) == str( NaT )         # False
   str( NaT )   == str( date1 )       # False

wait for it...

   str( NaT )   == str( Nat )         # True    (hooray!)