一般父類使用self.__class__去調(diào)用某一個(gè)屬性或者方法, 簡單的理解就是調(diào)用它子類的方法和屬性.

class Foo(object):
    def create_new(self):
        return self.__class__()

    def create_new2(self):
        return Foo()

class Bar(Foo):
    pass

b = Bar()
c = b.create_new()
print type(c)  # We got an instance of Bar
d = b.create_new2()
print type(d)  # we got an instance of Foo