Python: Access second parent's instance attribute

Question

I have class which inherits from 2 classes, but in child class instance I cant access second parent's instance attribute, here is my code example

class Parent1:
    def __init__(self):
        self.a = 'a'
        

class Parent2:
    def __init__(self):
        self.b = 'b'
        
class Child(Parent1, Parent2):
    pass

instance = Child()

print(instance.a)
print(instance.b) # here is error

is there actually clean way around?.

P.S: What i am actually doing is in django. In views I want to put extra parent class which will add some attributes to the view class instance

class ContextMixin:
    def __init__(self):
        self.context = {
            'data': None,
            'message': None
        }

# and in all/some views do like that
class LoginView(APIView, ContextMixin):
    def post(self, request):
        # use self.context instead of creating each time
        pass