enum.py

def Enum(**kwargs):
    values = kwargs
    class EnumClass(type):
        def __new__(cls, name, parents, dct):
            # create a class_id if it's not specified
            if 'class_id' not in dct:
                dct['class_id'] = name.lower()

            # we need to call type.__new__ to complete the initialization
            new_type = super(EnumClass, cls).__new__(cls, name, parents, dct)

            # set the values. assumes new_type.__init__(superclass_value)
            for value_name, value in values.items():
                setattr(cls, value, new_type(value))

            return new_type
    return EnumClass

class Action(str):
    __metaclass__ = Enum(
        Store="store",
        Append="append"
    )

print Action.Store, type(Action.Store)
    
# >>> "store", <class '__main__.Action'>