一文带你了解Python中的枚举(enum)

class color():
    YELLOW  = 1
    RED     = 2
    GREEN   = 3
    PINK    = 4
 
# 访问枚举项
print(color.YELLOW) # 1

class color():
    YELLOW  = 1
    YELLOW  = 3   # 注意这里又将YELLOW赋值为3，会覆盖前面的1
    RED     = 2
    GREEN   = 3
    PINK    = 4
 
# 访问枚举项
print(color.YELLOW) # 3
 
# 但是可以在外部修改定义的枚举项的值，这是不应该发生的
color.YELLOW = 99
print(color.YELLOW) # 99

# 导入枚举类
from enum import Enum
 
# 继承枚举类
class color(Enum):
    YELLOW  = 1
    BEOWN   = 1 
    # 注意BROWN的值和YELLOW的值相同，这是允许的，此时的BROWN相当于YELLOW的别名
    RED     = 2
    GREEN   = 3
    PINK    = 4
 
class color2(Enum):
    YELLOW  = 1
    RED     = 2
    GREEN   = 3
    PINK    = 4

print(color.YELLOW) # color.YELLOW
print(type(color.YELLOW)) # <enum 'color'>
 
print(color.YELLOW.value)  # 1
print(type(color.YELLOW.value)) # <class 'int'>
 
print(color.YELLOW == 1)    # False
print(color.YELLOW.value == 1)  # True
print(color.YELLOW == color.YELLOW)  # True
print(color.YELLOW == color2.YELLOW)  # False
print(color.YELLOW is color2.YELLOW)  # False
print(color.YELLOW is color.YELLOW)  # True
 
print(color(1))         # color.YELLOW
print(type(color(1)))   # <enum 'color'>
　　注意事项如下：

color.YELLOW = 2  # Wrong, can't reassign member

from enum import IntEnum

from enum import Enum, unique