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 consideredTrue.

Boolean operations

A Boolean operation returns a value of either True or False. Boolean operations are ordered in priority, so if more than one Boolean operation occurs in an expression, the operation with the highest priority will occur first. The following table outlines the three Boolean operators in descending order of priority:

Operator	Example
not x	Returns True if x is False; returns False otherwise.
x and y	Returns True if both x and y are True; returns False otherwise.
x or y	Returns True if either x or y is True; returns False...