Python Enum 枚举 用法汇总

Python Enum 枚举 用法汇总

 import os
 import sys
 if sys.version_info.major + sys.version_info.minor * 0.1 < 3.4:
     from enum34 import Enum
 else:
     from enum import Enum

 class MyColorEnum(Enum):
     red = 1
     red_alias = 1
     blue = 2
     green = 'green'

 MyColorEnum.red.name    # get member name string
 MyColorEnum.red.value   # get member value

 for c in MyColorEnum:
     print(c)    # just one of MyColorEnum.red_alias and MyColorEnum.red, according to the order which itself decides

 for c in MyColorEnum.__members__.items():
     c[0]    # str name eg. 'red'
     c[1]    # member eg. MyColorEnum.red
     # contain 'red_alias' and MyColorEnum.red_alias

 'red' in MyColorEnum.__members__    # if member name in Enum
 0 in MyColorEnum._value2member_map_ # if value in Enum values

 MyColorEnum.__members__['red']  # MyColorEnum.red, get member by member name string, if no such member name string, raising KeyError

 # comparation ################################################################################
 MyColorEnum.red is MyColorEnum.red_alias    # True
 MyColorEnum.red == MyColorEnum.red_alias    # True
 MyColorEnum.red != MyColorEnum.red_alias    # False
 #never do this
 #MyColorEnum.red < MyColorEnum.blue  # raising TypeError, Enum values could be different types