Python“和"带整数的运算符
问题描述
在 Python 中这种行为的解释是什么?
What is the explanation for this behavior in Python?
a = 10
b = 20
a and b # 20
b and a # 10
a and b 计算结果为 20,而 b and a 计算结果为 10.正整数是否等同于 True?为什么它评估为第二个值?因为它是第二?
a and b evaluates to 20, while b and a evaluates to 10. Are positive ints equivalent to True? Why does it evaluate to the second value? Because it is second?
解决方案
文档解释这很好:
表达式x and y首先计算x;如果 x 为 false,则返回其值;否则,评估 y 并返回结果值.
The expression
x and yfirst evaluatesx; ifxis false, its value is returned; otherwise,yis evaluated and the resulting value is returned.
or 也是如此,这可能是你的下一个问题.
And similarly for or which will probably be the next question on your lips.
表达式x or y首先计算x;如果 x 为真,则返回其值;否则,评估 y 并返回结果值.
The expression
x or yfirst evaluatesx; ifxis true, its value is returned; otherwise,yis evaluated and the resulting value is returned.
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