【Class 16】枚举

实例一： 定义一个枚举

from enum import Enum

class VIP(Enum):
    YELLOW = 1
    GREEN = 2
    BLACK = 3
    RED = 4

print(VIP.YELLOW)
print(VIP.BLACK)

print('--------')
for i in VIP:
    print(i)

打印结果：
VIP.YELLOW
VIP.BLACK
--------
VIP.YELLOW
VIP.GREEN
VIP.BLACK
VIP.RED

实例二： 枚举可以有相同的值（别名），但一般不会打印出来

from enum import Enum

class VIP(Enum):
    YELLOW = 1
    YELLOW_ALIAS = 1
    GREEN = 2
    BLACK = 3
    RED = 4

# 此时打印所有枚举，则别名不会被打印出来
for i in VIP:
    print(i)

# 以元组的形式，将枚举所有值打印出来，包括别名
for i in VIP.__members__.items():
    print(i)

打印结果：
VIP.YELLOW
VIP.GREEN
VIP.BLACK
VIP.RED
('YELLOW', <VIP.YELLOW: 1>)
('YELLOW_ALIAS', <VIP.YELLOW: 1>)
('GREEN', <VIP.GREEN: 2>)
('BLACK', <VIP.BLACK: 3>)
('RED', <VIP.RED: 4>)