Typeerror: Cannot Create a Consistent Method Resolution Order (Mro)

TypeError: Cannot create a consistent method resolution order (MRO)

Your GameObject is inheriting from Player and Enemy. Because Enemy already inherits from Player Python now cannot determine what class to look methods up on first; either Player, or on Enemy, which would override things defined in Player.

You don't need to name all base classes of Enemy here; just inherit from that one class:

class GameObject(Enemy):
    pass

Enemy already includes Player, you don't need to include it again.

Cannot create a consistent method resolution order (MRO) for bases Widget, Screen when using ScreenManager in kivy

Your code:

class Test1(Widget, Screen):

is trying to extend both Widget and Screen, but Screen is a Widget, so you don't need Widget. Try changing the above code to:

class Test1(Screen):

and similar for Test2.

Cannot create a consistent method resolution.. Why?

D inherits A and B and both have a function say_hello. And B inherits from A.

You can't multiply inherit from a base class followed by a derived class

It's impossible to define a consistent MRO that satisfies the usual MRO constraints/guarantees. As described here

You now call super(D, self).say_hello() and python does not know which say_hello to pick.

A or B?!

This as example would work:

class D(A): #D only inherits A not A and B
    def say_hello(self):
        super(D, self).say_hello()
        print 'D says hello'

DD = D()
DD.say_hello()

#output
>>>A says hello
>>>D says hello

#There are 2 connections to As say_hello
    A-----
   / \   |
  B   C  |
  |     /
  \    / 
    D

PS: Please use "self" as name for the first parameter

Update:
It would pick As say_hello if the inheritance would look something like this

class A(object):
    def say_hello(cls):
        print 'A says hello'

class B():
     def say_hello(cls):
        print 'B says hello'

class C(B):
    def say_hello(cls):
        super(C, cls).say_hello()
        print 'C says hello'

class D(A, C):
    def say_hello(self):
        super(D, self).say_hello()
        print 'D says hello'

DD = D()
DD.say_hello()

Inheritance-tree:

    A
  /
  |   B
  |   |
  |   C
  \   / 
    D

Python now picks the say_hello with the least specialization e.g. A.

A consistent Method Resolution Order couldn't be created (MRO error)

childB is attempting to inherit from Base twice, once through childA and once directly. Fix by removing the multiple inheritance on childB.

class Base(object):
    def __init__(self):
        print ("Base")

class childA(Base):
    def __init__(self):
        print ('Child A')
        Base.__init__(self)

class childB(childA):
    def __init__(self):
        print ('Child B')
        super(childB, self).__init__()

b=childB()

TypeError: Cannot create a consistent method resolution in django

In Python, every class inherits from a built-in basic class called object.

Your OwnerCourseMixin is inheriting from object and some other class. Because the other class(es), in this case, LoginRequiredMixin and PermissionRequiredMixin, already inherit from object, Python now cannot determine what class to look methods up on first.

You don't need to inherit from object here.

class OwnerCourseMixin(LoginRequiredMixin, PermissionRequiredMixin):
    model = Course
    fields = ['subject', 'title', 'slug', 'overview']
    success_url = reverse_lazy('manage_course_list')

That should work.

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