两个布尔列表之间的逻辑运算 [英] Logical operation between two Boolean lists

问题描述

我得到一个奇怪的结果，我尝试将and或or运算符应用于python中的2个布尔值列表.实际上，我得到的与预期完全相反.

I get a weird result and I try to apply the and or the or operator to 2 Boolean lists in python. I actually get the exact opposite of what I was expecting.

[True, False, False] and [True, True, False]
> [True, True, False]

[True, False, False] or [True, True, False]
> [True, False, False]

那正常吗?如果是，为什么?

Is that normal, and if yes, why?

推荐答案

您的列表不是比较每个单独的值，而是比较列表中值的存在.

Your lists aren't comparing each individual value, they're comparing the existence of values in the list.

对于任何真实变量a和b:

a and b
> b #The program evaluates a, a is truthy, it evaluates b, b is truthy, so it returns the last evaluated value, b.
a or b
> a #The program evaluates a, a is truthy, so the or statement is true, so it returns the last evaluated value, a.

现在，真实性取决于类型.例如，整数对于my_int != 0是真实的，而对于my_int == 0是虚假的.因此，如果您有:

Now, truthy depends on the type. For example, integers are truthy for my_int != 0, and are falsy for my_int == 0. So if you have:

a = 0
b = 1
a or b
> b #The program evaluates a, a is falsy, so the or statement goes on to evaluate b, b is truthy, so the or statement is true and it returns the last evaluated value b.

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