super（）失败并出现错误：TypeError"参数1必须是type，而不是classobj"当父不从对象继承时 [英] super() fails with error: TypeError "argument 1 must be type, not classobj" when parent does not inherit from object

问题描述

我得到一些我无法弄清楚的错误。我的示例代码有什么问题吗？

I get some error that I can't figure out. Any clue what is wrong with my sample code?

class B:
    def meth(self, arg):
        print arg

class C(B):
    def meth(self, arg):
        super(C, self).meth(arg)

print C().meth(1)

我从帮助中获得了示例测试代码'超'内置方法。 C类是

I got the sample test code from help of 'super' built-in method. The class "C" is the

这是错误：

Traceback (most recent call last):
  File "./test.py", line 10, in ?
    print C().meth(1)
  File "./test.py", line 8, in meth
    super(C, self).meth(arg)
TypeError: super() argument 1 must be type, not classobj

仅供参考，这是帮助（超级）来自python本身：

FYI, here is the help(super) from python itself:

Help on class super in module __builtin__:

class super(object)
 |  super(type) -> unbound super object
 |  super(type, obj) -> bound super object; requires isinstance(obj, type)
 |  super(type, type2) -> bound super object; requires issubclass(type2, type)
 |  Typical use to call a cooperative superclass method:
 |  class C(B):
 |      def meth(self, arg):
 |          super(C, self).meth(arg)
 |

推荐答案

您的问题是B类未被声明为新式课程。像这样更改：

Your problem is that class B is not declared as a "new-style" class. Change it like so:

class B(object):

它会起作用。

super（）并且所有子类/超类的东西只适用于新式类。我建议你养成在任何类定义上输入（object）的习惯，以确保它是一个新式的类。

super() and all subclass/superclass stuff only works with new-style classes. I recommend you get in the habit of always typing that (object) on any class definition to make sure it is a new-style class.

旧式类（也称为经典类）的类型始终为 classobj ;新式类的类型为类型。这就是您收到错误消息的原因：

Old-style classes (also known as "classic" classes) are always of type classobj; new-style classes are of type type. This is why you got the error message you saw:

TypeError：super（）参数1必须是type，而不是classobj

试试看你自己：

class OldStyle:
    pass

class NewStyle(object):
    pass

print type(OldStyle)  # prints: <type 'classobj'>

print type(NewStyle) # prints <type 'type'>

请注意，在Python 3.x中，所有类都是新式的。您仍然可以使用旧式类的语法，但是您将获得一个新式类。所以，在Python 3.x中你不会遇到这个问题。

Note that in Python 3.x, all classes are new-style. You can still use the syntax from the old-style classes but you get a new-style class. So, in Python 3.x you won't have this problem.

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