Implementing enumerations in Python using metaclasses.

enum_meta.py

class EnumMetaDict(dict):

    def __init__(self):
        self.n = -1

    def __getitem__(self, item):
        if item.isupper():
            self.n += 1
            self[item] = self.n
            return self.n
        return super().__getitem__(item)
    
class EnumMeta(type):
    
    @classmethod
    def __prepare__(meta, name, bases):
        return EnumMetaDict()

class Enum(metaclass = EnumMeta):
    pass