[Gretl-users] Re: if condition: evaluating NA values

.... Python does not throw an error and returns "1" <python> import math foo = math.nan actual = 0 if foo:      actual += 1 print(actual) </python> So, two of the three languages I used throw an error. Python is known for its rather "sloppy" handling of types :-D ....  Python has the "everything is an object, except None" rule. You are not testing for boolean but the existence of objects. foo = None if foo:     print("foo exists") import math bar = math.nan if bar:      print("bar exists") >>>bar exists