enum.py

class EnumItem(object):
    def __init__(self, name, value):
        self.name  = name
        self.value = value

class Enum(type):
    def __init__(self, name, bases, dict):
        super(Enum, self).__init__(name, bases, dict)
        self.collection = {}

        if hasattr(self, '__items__'):
            for value, item in enumerate(self.__items__):
                self.add_value(item, value)
        else:
            for k in dict:
                if k[0] != '_' and isinstance(dict[k], (int, float, str)):
                    self.add_value(k, dict[k])

    def __call__(self, *args, **kwargs):
        return self

    def __iter__(self):
        return iter(self.values)

    def __getitem__(self, name):
        if name not in self.collection:
            raise KeyError('%s not a member of enumeration' % name)

        return self.collection[name].value

    def add_value(self, name, value):
        if value in self.values:
            raise ValueError('Value %s enumerated more than once' % str(value))
        
        self.collection[name] = EnumItem(name, value)
    
    @property
    def values(self):
        return [i.value for i in self.collection.values()]

    @property
    def items(self):
        return [(i.name, i.value) for i in self.collection.values()]

    @property
    def names(self):
        return [i.name for i in self.collection.values()]
    
    def item(self, value):
        for k in self.collection:
            if self.collection[k].value == value:
                return self.collection[k]

        return None

    def item_by_name(self, name):
        return self.collection.get(name)

    def name(self, value):
        item = self.item(value)
        return item.name if item else None

    def label(self, value):
        item = self.item(value)
        return getattr(self.Labels, item.name) if item else None

    def label_by_name(self, name):
        item = self.collection.get(name)
        return getattr(self.Labels, item.name) if item else None

if __name__ == '__main__':

    import string
    class Foos:
        __metaclass__ = Enum
        __items__     = list(string.lowercase)

    print Foos.items

    class SetListNames:

        __metaclass__ = Enum

        SET1   = '1'
        SET2   = '2'
        ENCORE = 'e'

        class Labels:
            SET1   = 'Set 1'
            SET2   = 'Set 2'
            ENCORE = 'Encore'

    SetListNames.label(SetListNames.SET1)

    for value in SetListNames:
        print '%20s%20s%20s' % (value, SetListNames.label(value), SetListNames.name(value))

    print SetListNames['SET2']