Question

In Python, is there any to declare class members of the type being declared?

class Foo:
    def __init__(self, a, b):
        self.one = a
        self.two = b

    ZERO = Foo(0, 0)
    ONE = Foo(0, 1)

The problem seems to arise from the fact that the class Foo isn’t completely def’d at the time of evaluation for Foo.ZERO and Foo.ONE – is there any way to overcome this while maintaining the form of Foo.MEMBER?

Answer 1

This seems to work:

class Enum(object):
    def __init__(self, a, b): 
        self.one = a
        self.two = b 

    def __metaclass__(name, bases, dict):
        cls = type(name, bases, dict)
        cls.ZERO = cls(0, 0)
        cls.ONE = cls(0, 1)
        return cls