您可以使用元类：

class AutoRegister(type):

def __new__(mcs, name, bases, classdict):

new_cls = type.__new__(mcs, name, bases, classdict)

#print mcs, name, bases, classdict

for b in bases:

if hasattr(b, 'register_subclass'):

b.register_subclass(new_cls)

return new_cls

class AbstractClassA(object):

__metaclass__ = AutoRegister

_subclasses = []

@classmethod

def register_subclass(klass, cls):

klass._subclasses.append(cls)

@classmethod

def get_concrete_classes(klass):

return klass._subclasses

class ConcreteClassA1(AbstractClassA):

pass

class ConcreteClassA2(AbstractClassA):

pass

class ConcreteClassA3(ConcreteClassA2):

pass

print AbstractClassA.get_concrete_classes()

我个人非常警惕这种魔法.不要在代码中加入太多内容.