标签：不可变 rac 一个 imp spl false not 帮助 常量
Enum可以把一组相关常量定义在一个class中，且class不可变，而且成员可以直接比较。
定义枚举类：
from enum import Enum, unique @unique class Weekday(Enum): Sun = 0 # Sun的value被设定为0 Mon = 1 Tue = 2 Wed = 3 Thu = 4 Fri = 5 Sat = 6
可以看到括号里面是Enum ，即继承自枚举类
然后给这个枚举类的每个成员赋予一个值
@unique装饰器可以帮助我们检查保证没有重复值。
使用：
>>> day1 = Weekday.Mon >>> print(day1) Weekday.Mon >>> print(Weekday.Tue) Weekday.Tue >>> print(Weekday[‘Tue‘]) Weekday.Tue >>> print(Weekday.Tue.value) 2 >>> print(day1 == Weekday.Mon) True >>> print(day1 == Weekday.Tue) False >>> print(Weekday(1)) Weekday.Mon >>> print(day1 == Weekday(1)) True >>> Weekday(7) Traceback (most recent call last): ... ValueError: 7 is not a valid Weekday >>> for name, member in Weekday.__members__.items(): ... print(name, ‘=>‘, member) ... Sun => Weekday.Sun Mon => Weekday.Mon Tue => Weekday.Tue Wed => Weekday.Wed Thu => Weekday.Thu Fri => Weekday.Fri Sat => Weekday.Sat
标签：不可变 rac 一个 imp spl false not 帮助 常量
原文地址：https://www.cnblogs.com/xqxacm/p/9828700.html
