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Another way this error can occur is when you reload the module with the class in a Jupiter notebook.

Easy solution is to restart the kernel.

http://thomas-cokelaer.info/blog/2011/09/382/

Check out @Mike W's answer for more detail.

You should call super using the UrlManager class as first argument not the URL model. super cannot called be with an unrelated class/type:

From the docs,

super(type[, object-or-type]) : Return a proxy object that delegates method calls to a parent or sibling class of type.

So you cannot do:

>>> class D:
...    pass
>>> class C:
...    def __init__(self):
...        super(D, self).__init__()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 3, in __init__
TypeError: super(type, obj): obj must be an instance or subtype of type
You should do:
qs_main = super(UrlManager, self).all(*args, **kwargs)
Or in Python 3:
qs_main = super().all(*args, **kwargs)
                Is the traceback still the same? The one you've shown shows the error is from the all method of the manager, which I have addressed in my answer.
– Moses Koledoye
                May 3, 2017 at 5:13
                Haven't much used django lately, but I'm just wondering, is there a reason to use old styled classes here?
– 0xc0de
                Nov 10, 2017 at 11:11
Elaborating in @Oğuz Şerbetci's answer, in python3 (not necessary only in Jupyter), when there is the need to reload a library, for example we have class Parent and class Child defined as
class Parent(object):
    def __init__(self):
        # do something
class Child(Parent):
    def __init__(self):
        super(Child, self).__init__(self)
then if you do this
import library.Child
reload(library)
Child()
you will get TypeError: super(type, obj): obj must be an instance or subtype of type, the solution is just to re import the class after the reload
import library.Child
reload(library)
import library.Child
Child()
                Hi, any idea how this would work with autoreload magics? %reload_ext autoreload, %autoreload 2
– Eric Burel
                Jan 21, 2020 at 9:16
You can get his issue in because reload logic have some bugs (issue)

Here is a simple solution/workaround that works for me until issue is not fixed 
Add typo like 1001xx at the bottom of the file which you call in the cell 
Run your cell - you will see some exception, just skip it
Remove typo which was added on step 1
Run the cell
Profit
The best solution that I have found for this problem is only available using python 3. You then don't need to specify the arguments of "super", then you won't have the error any more writing your class like this :
class D:
class C(D):
    def __init__(self):
        super().__init__()# no arguments given to super()
Another interesting way is if a merge of branches has duplicated the class, so that in the file you have two definitions for the same name, e.g.
class A(Foo):
    def __init__(self):
        super(A, self).__init__()
class A(Foo):
    def __init__(self):
        super(A, self).__init__()
If you try to create an instance from a static reference to the first definition of A, once it tries to call super, inside the __init__ method, A will refer to the second definition of A, since it has been overwritten. The solution - ofcourse - is to remove the duplicate definition of the class, so it doesn't get overwritten.
This may seem like something that would never happen, but it just happened to me, when I wasn't paying close enough attention to the merge of two branches. My tests failed with the error message described in the question, so I thought I'd leave my findings here, even though it doesn't exactly answer the specific question.
This error also pops out when you simply do not instantiate child class
, and try to call a method on a class itself, like in :
class Parent:
    def method():
class Child(Parent):
    def method():
        super().method()
P = Parent()
C = Child
C.method()
                Thanks. This is particular tricky if you are using a class which does not have any member variables. For instance, everything is at-staticmethod or at-classmethod decrator. Then you might be inclined to just call MyInstance.mymethod instead of MyInstance().mymethod (note the brackets)
– toobee
                Jun 21, 2022 at 13:01
Similar to @Eldamir, I solved it by realizing I had written two classes with the same name, and the second one was overwriting the first.
If that's the case, change the name of one of the classes.
So I just pasted in a form in forms.py.
I just made a fast look to see if I needed to change anything, but I didn't see that.
Then I got this super(type, obj): obj must be an instance or subtype of type error, so I searched for it on the browser, but before I checked any of the answers I looked one more time and this time I spotted the issue.
As you can see, many answers on this question says it was wrong with the super. Yes it was the same issue for me.
make sure that you look if you have any super and see if the class added matches with the class. At least that's what I did.
Before and After
Where I spotted it in my code
forms.py
Before:
class userProfileForm(ModelForm):
    class Meta:
        model = user_profile
        fields = ("user", "rating", )
    def __init__(self, *args, **kwargs):
        # https://stackoverflow.com/a/6866387/15188026
        hide_condition = kwargs.pop('hide_condition',None)
        super(ProfileForm, self).__init__(*args, **kwargs)
        if hide_condition:
            self.fields['user'].widget = HiddenInput()
After:
class userProfileForm(ModelForm):
    class Meta:
        model = user_profile
        fields = ("user", "rating", )
    def __init__(self, *args, **kwargs):
        # https://stackoverflow.com/a/6866387/15188026
        hide_condition = kwargs.pop('hide_condition',None)
        super(userProfileForm, self).__init__(*args, **kwargs)
        if hide_condition:
            self.fields['user'].widget = HiddenInput()
You see that the super got changed to the class name
        # define forward pass
The class name should match the written class inside the super function. In this case, A_net is the class.
It works for me.
        
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