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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:
Both the and operator and the or operator use "short-circuiting" when evaluating an expression. This means Python will only evaluate an operator if it needs to. For example, if x is True then in an expression x or y, the y does not get evaluated since the expression is obviously True. In a similar way, in an expression x and y where x is False, the interpreter will simply evaluate x and return False, without evaluating y.