out[ ](falsetruein [ ]bool('hello world!')bool(''out[ ](truefalsein [ ]bool( )bool( out[ ](falsetruetype casting the strboolint and float types are also functions which can be used to cast values to those typesin [ ] ' in [ ]fval float(sin [ ]int(fvalout[ ] in [ ]type(fvalout[ ]float in [ ]bool(fvalout[ ]true in [ ]bool( out[ ]false none none is the python null value type if function does not explicitly return valueit implicitly returns none in [ ] none in [ ] is none out[ ]true in [ ] in [ ] is not none out[ ]true none is also common default value for optional function argumentsdef add_and_maybe_multiply(abc=none)result if is not noneresult result return result while technical pointit' worth bearing in mind that none is not reserved keyword but rather unique instance of nonetype dates and times the built-in python datetime module provides datetimedateand time types the datetime type as you may imagine combines the information stored in date and time and is the most commonly usedin [ ]from datetime import datetimedatetime in [ ]dt datetime( the basics www it-ebooks info