Python中模拟enum枚举类型的5种方法分享

以下几种方法来模拟enum：（感觉方法一简单实用）

# way1

class Directions:

    up = 0

    down = 1

    left = 2

    right =3

    

print Directions.down
# way2

dirUp, dirDown, dirLeft, dirRight = range(4)
print dirDown
# way3

import collections

dircoll=collections.namedtuple('directions', ('UP', 'DOWN', 'LEFT', 'RIGHT'))

directions=dircoll(0,1,2,3)
print directions.DOWN
# way4

def enum(args, start=0):

    class Enum(object):

        __slots__ = args.split()
        def __init__(self):

            for i, key in enumerate(Enum.__slots__, start):

                setattr(self, key, i)
    return Enum()
e_dir = enum('up down left right')
print e_dir.down
# way5

# some times we need use enum value as string

Directions = {'up':'up','down':'down','left':'left', 'right':'right'}
print Directions['down']