super fails with error TypeError argument 1 must be type not classobj when parent does not inherit from object

Question

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    I got the sample test code from help of  super  built-in method    Here is the error   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   FYI  here is the help super  from python itself   Help on class super in module   builtin     class super object      super type  - gt  unbound super object     super type  obj  - gt  bound super object  requires isinstance obj  type      super type  type2  - gt  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

User · Answer

Also  if you can t change class B  you can fix the error by using multiple inheritance   class B      def meth self  arg           print arg  class C B  object       def meth self  arg           super C  self  meth arg   print C   meth 1

User · Answer

I was also faced by the posted issue when I used python 2 7  It is working very fine with python 3 4  To make it work in python 2 7 I have added the   metaclass     type attribute at the top of my program and it worked     metaclass     It eases the transition from old-style classes and new-style classes

User · Answer

Your problem is that class B is not declared as a  new-style  class   Change it like so   class B object     and it will work   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   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   argument 1 must be type  not classobj  Try this to see for yourself   class OldStyle      pass  class NewStyle object       pass  print type OldStyle     prints   lt type  classobj  gt   print type NewStyle    prints  lt type  type  gt    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

User · Answer

If the python version is 3 X  it s okay   I think your python version is 2 X  the super would work when adding this code    metaclass     type   so the code is    metaclass     type class B      def meth self  arg           print arg class C B       def meth self  arg           super C  self  meth arg  print C   meth 1

[python] super() fails with error: TypeError "argument 1 must be type, not classobj" when parent does not inherit from object

Examples related to python

Examples related to object

Examples related to inheritance

Examples related to parent

Examples related to super