Static Data?

[Jeff Epler]

class Counted:
    _ID = 0

    def __init__(self):
        Counted._ID += 1
        self._ID = Counted._ID

>>> o1, o2, o3 = [Counted() for i in range(3)]
>>> [o._ID for o in (o1, o2, o3)]
[1, 2, 3]

Jeff