Operations and expressions

There are a number of operations that are common to all data types. For example, all data types, and generally all objects, can be tested for a truth value in some way. The following are values that Python considers False:

• The None type
• False
• An integer, float, or complex zero
• An empty sequence or mapping
• An instance of a user-defined class that defines a __len__() or __bool__() method that returns zero or False

All other values are considered True.