一文带你了解Python枚举类enum的使用_python_

from enum import Enum class Color(Enum): RED = 1 GREEN = 2 BLUE = 3 print(Color.RED) # Color.RED print(repr(Color.RED)) #  print(type(Color.RED)) #  print(isinstance(Color.GREEN, Color)) # True print(Color.RED.name) # RED 

from enum import Enum class Shake(Enum): VANILLA = 7 CHOCOLATE = 4 COOKIES = 9 MINT = 3 for shake in Shake: print(shake) # Shake.VANILLA # Shake.CHOCOLATE # Shake.COOKIES # Shake.MINT 

from enum import Enum class Shape(Enum): SQUARE = 2 DIAMOND = 1 CIRCLE = 3 ALIAS_FOR_SQUARE = 2 for name, member in Shape.__members__.items(): print(name, member) # SQUARE Shape.SQUARE # DIAMOND Shape.DIAMOND # CIRCLE Shape.CIRCLE # ALIAS_FOR_SQUARE Shape.SQUARE 

from enum import Enum class Color(Enum): RED = 1 GREEN = 2 BLUE = 3 apples = {} apples[Color.RED] = 'red delicious' apples[Color.GREEN] = 'granny smith' print(apples) # {: 'red delicious', : 'granny smith'} 

from enum import Enum class Color(Enum): RED = 1 GREEN = 2 BLUE = 3 # 通过值访问 print(Color(1)) # Color.RED print(Color(3)) # Color.BLUE # 通过name访问 print(Color['RED']) # Color.RED print(Color['GREEN']) # Color.GREEN # 访问成员的name或value print(Color.RED.name) # RED print(Color.RED.value) # 1 

from enum import Enum, unique @unique class Mistake(Enum): ONE = 1 TWO = 2 THREE = 3 FOUR = 3 # ValueError: duplicate values found in : FOUR -> THREE 

from enum import Enum, auto class Color(Enum): RED = auto() BLUE = auto() GREEN = auto() print(Color(1)) # Color.RED print(list(Color)) # [, , ] 

from enum import Enum class Color(Enum): RED = 1 BLUE = 2 GREEN = 3 print(Color.RED is Color.RED) # True print(Color.RED is Color.BLUE) # False print(Color.RED is not Color.BLUE) # True try: Color.RED < Color.BLUE # Enum不支持直接排序 except Exception as e: print(e) # '<' not supported between instances of 'Color' and 'Color' print(Color.BLUE == Color.RED) # Fasle print(Color.BLUE != Color.RED) # True print(Color.BLUE == Color.BLUE) # True print(Color.BLUE == 2) # False 

from enum import IntEnum class Color(IntEnum): RED = 1 BLUE = 2 GREEN = 3 # IntEnum可直接排序 print(Color.RED < Color.BLUE) # True print(Color.BLUE == 2) # True 

from enum import Enum class Animal(Enum): ANT = 1 BEE = 2 CAT = 3 DOG = 4 Animal = Enum('Animal', 'ANT BEE CAT DOG') # 同上 print(Animal) #  print(Animal.ANT) #  print(Animal.ANT.value) # 1 print(list(Animal)) # [, , , ] 

from enum import Enum, IntEnum class Color(Enum): RED = 1 GREEN = 2 class Shape(IntEnum): CIRCLE = 1 SQUARE = 2 class Request(IntEnum): POST = 1 GET = 2 print(Shape.CIRCLE == Color.RED) # False print(Shape == 1) # False print(Shape.CIRCLE == 1) # True print(Shape.CIRCLE == Request.POST) # True print(int(Shape.CIRCLE)) # 1 print(['a', 'b', 'c'][Shape.CIRCLE]) # b print([i for i in range(Shape.SQUARE)]) # [0, 1] 

from enum import IntFlag class Perm(IntFlag): R = 4 # 读 W = 2 # 写 X = 1 # 执行 print(Perm.R | Perm.W) #  print(Perm.R + Perm.W) # 6 RW = Perm.R | Perm.W print(Perm.R in RW) # True 

from enum import IntFlag class Perm(IntFlag): R = 4 # 读 W = 2 # 写 X = 1 # 执行 RWX = 7 # 读写执行 print(Perm.RWX) #  print(~Perm.RWX) #  print(Perm.R & Perm.X) #  print(bool(Perm.R & Perm.X)) # False print(Perm.X | 8) # 

from enum import Flag, auto class Color(Flag): BLACK = 0 RED = auto() BLUE = auto() GREEN = auto() WHITE = RED | BLUE | GREEN print(Color.RED & Color.GREEN) #  print(bool(Color.RED & Color.GREEN)) # False print(Color.WHITE) #  print(Color.BLACK) #  print(bool(Color.BLACK)) # False