Why does this boolean expression evaluate to False?

Question

Can someone explain to me why the Python interpreter evaluates this expression to be False?

1 in [1] == True

I would expect that 1 in [1] would evaluate to True, and obviously True == True would be True. However this isn't what happens - the expression is False. Why does this happen?

Answer 1

==并且in都是比较运算符。并且当您有多个这样的比较运算符时，Python会将其视为链式比较。例如，1 < x < 10等效于1 < x and x < 10。

就您而言，1 in [1] == True等于(1 in [1]) and ([1] == True)，其结果为False。