是&和< and>等价于python? [英] Are & and <and> equivalent in python?

问题描述

在Python中使用和一词与& 符号的逻辑或性能是否存在差异?

Is there any difference in the logic or performance of using the word and vs. the & symbol in Python?

推荐答案

and 是布尔运算符.它将两个参数都视为布尔值，如果错误则返回第一个，否则返回第二个.请注意，如果第一个参数是虚假的，那么第二个参数甚至都不会计算，这对于避免副作用很重要.

and is a Boolean operator. It treats both arguments as Boolean values, returning the first if it's falsy, otherwise the second. Note that if the first is falsy, then the second argument isn't even computed at all, which is important for avoiding side effects.

示例:

• False和True->错误
• True and True->正确
• 1和2->2
• False和None.explode()->错误(也不例外)

• False and True --> False
• True and True --> True
• 1 and 2 --> 2
• False and None.explode() --> False (no exception)

& 具有两种行为.

• 如果两个都是 int ，则它将计算两个数字的按位与，并返回一个 int .如果一个是 int ，一个是 bool ，则将 bool 的值强制转换为int(为0或1)，并且应用相同的逻辑.
• 否则，如果两个都是 bool ，则将评估两个参数并返回 bool .
• 否则会引发 TypeError (例如 float& float 等).

• If both are int, then it computes the bitwise AND of both numbers, returning an int. If one is int and one is bool, then the bool value is coerced to int (as 0 or 1) and the same logic applies.
• Else if both are bool, then both arguments are evaluated and a bool is returned.
• Otherwise a TypeError is raised (such as float & float, etc.).

示例:

• 1&2->0
• 1&正确->1&1->1
• True&2->1&2->0
• True&正确->正确
• False&None.explode()->AttributeError:'NoneType'对象没有属性'explode'

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