在Python3中，

a = b = 3
a is None == b is None

返回False，但是

(a is None) == (b is None)

返回True。因此，我想仅基于此示例，==优先于 is 。

然而，

a = b = None
a is None == b is None

返回True。和

(a is None) == (b is None)

返回True。但

a is (None == b) is None

返回False。在这种情况下，它会看起来好像 是 有优先级高于==。

再举一个例子，这个表达并不意味着要做什么，但是请忍受我。如果我说

None is None == None

它返回True。但是以下两个都返回False。

None is (None == None)
(None is None) == None

显然，Python并没有严格地评估它们，但是我对正在发生的事情感到困惑。它如何使用2个不同的运算符来评估此表达式，但是这两个顺序都不相同？

1 < a < 3

None is None == None

(None is None) and (None == None)

a = b = 3
a is None == b is None

(a is None) and (None == b) and (b is None)