python enum implement in 2.x

python_enum.py

def enum(*sequential, **named):
    """ 创建自定义枚举类型，支持两种用法:
    1. enum('Success', 'Failed')
       会从0开始给Success,Failed分配0,1两个值

    2. enum(on=1, off=0)
       指定on,off两个枚举的值

    创建枚举类之后,可以通过调用 set_alias 方法设置枚举值对应的别名, 然后通过 get_alias 获取某个枚举值对应的别名
    """
    enums = dict(zip(sequential, range(len(sequential))), **named)
    reverse = dict((value, key) for key, value in enums.iteritems())
    enums['reverse_mapping'] = reverse
    @classmethod
    def set_alias_func(clz, **alias):
        setattr(clz, '__alias', dict(map(lambda p:(getattr(clz,p[0]),p[1]), alias.iteritems())))
    enums['set_alias'] = set_alias_func
    @classmethod
    def get_alias_func(clz, key):
        return getattr(clz, '__alias')[key]
    enums['get_alias'] = get_alias_func
    return type('Enum', (object,), enums)