I've just found out that a subclass shares the class variables of its superclass until it's instantiated for the first time, but not any more afterwards:
Python 3.1 (r31:73574, Jun 26 2009, 20:21:35) [MSC v.1500 32 bit (Intel)] on win32 Type "help", "copyright", "credits" or "license" for more information. >>> class A: ... n = 0 ... def __init__(self): ... type(self).n += 1 >>> class B(A): ... pass >>> A.n, B.n (0, 0) >>> (A().n, A.n, B.n), (A().n, A.n, B.n), (B().n, A.n, B.n) ((1, 1, 1), (2, 2, 2), (3, 2, 3)) >>> (A().n, A.n, B.n), (A().n, A.n, B.n), (B().n, A.n, B.n) ((3, 3, 3), (4, 4, 3), (4, 4, 4)) >>> (A().n, A.n, B.n), (A().n, A.n, B.n), (B().n, A.n, B.n) ((5, 5, 4), (6, 6, 4), (5, 6, 5)) This makes no sense to me at all. Could it possibly be a bug? -- http://mail.python.org/mailman/listinfo/python-list
