Python利用new创建一个类的对象

class MyClass(BaseClass):
    def __new__(cls, *args, **kwargs):
        return super(MyClass, cls).__new__(cls, *args, **kwargs)

super并不是一个函数，而是一个类名，形如super(B, cls)事实上调用了super类的初始化函数，产生了一个super对象。Python Manuals上介绍：
super(type[, object-or-type])
Return a proxy object that delegates method calls to a parent or sibling class of type.
Note: super() only works for new-style classes.

super接收两个参数，两个参数的类型之间需要有继承关系，否则会报：
TypeError: super(type, obj): obj must be an instance or subtype of type  

T.__new__(S, ...) return a new object with type S, a subtype of T