你想使用小部件.__子类__（）获取所有子类的列表。它只查找直接子类，但如果你想要所有这些，你将不得不做更多的工作：

You want to use Widget.__subclasses__() to get a list of all the subclasses. It only looks for direct subclasses though so if you want all of them you'll have to do a bit more work:

def inheritors(klass):
    subclasses = set()
    work = [klass]
    while work:
        parent = work.pop()
        for child in parent.__subclasses__():
            if child not in subclasses:
                subclasses.add(child)
                work.append(child)
    return subclasses

NB如果您使用的是Python 2.x，则仅适用于新式类。

N.B. If you are using Python 2.x this only works for new-style classes.