Yes, you can do it. An interface can extend multiple interfaces, as shown here: interface Maininterface extends inter1, inter2, inter3 { // methods } A single class can also implement multiple interfaces. What if two interfaces have a method defining the same name and signature? There is a tricky point: interface A { void test(); … Read more
This has nothing to do with overriding functions. It has to do with conversions. It really doesn’t have to do with accessibility (i.e “private” or such) directly either. Here is a simpler example struct A { int a; }; struct B : A { }; struct C : B, A { }; // direct A … Read more
The problem in your case is that the classes you try to inherit from have different metaclasses: >>> type(QStandardItem) <class ‘sip.wrappertype’> >>> type(ConfigParser) <class ‘abc.ABCMeta’> Therefore python can’t decide which should be the metaclass for the newly created class. In this case, it would have to be a class inheriting from both sip.wrappertype (or PyQt5.QtCore.pyqtWrapperType … Read more
That’s not what super() is for. Super basically picks one (or all) of its parents in a specific order. If you only want to call a single parent’s method, do this class ASDF(ASDF1, ASDF2, ASDF3): def __init__(self): ASDF2.__init__(self)
Instead of using the recipe as mentioned by jdi, you can directly use: class M_C(M_A, M_B): pass class C(A, B): __metaclass__ = M_C
It seem to be impossible for now. You can find a discussion about “Intersection” type in python/typing#123 repository. There is a similar feature on PEP-544 called Protocol, and you can merge mixins by merging mixin protocols. There is an implementation of PEP-544 called typing_extensions. Maybe you can try that with this library.
This problem doesn’t come up very often. The solution I’m familiar with was designed by Doug McIlroy and appears in Bjarne Stroustrup’s books (presented in both Design & Evolution of C++ section 12.8 and The C++ Programming Language section 25.6). According to the discussion in Design & Evolution, there was a proposal to handle this … Read more
Sorry, you cannot inherit from multiple classes. You may use interfaces or a combination of one class and interface(s), where interface(s) should follow the class name in the signature. interface A { } interface B { } class Base { } class AnotherClass { } Possible ways to inherit: class SomeClass : A, B { … Read more
Change your code to this and I think it’ll explain things (presumably super is looking at where, say, B is in the __mro__?): class A(object): def __init__(self): print “A init” print self.__class__.__mro__ class B(A): def __init__(self): print “B init” print self.__class__.__mro__ super(B, self).__init__() class C(A): def __init__(self): print “C init” print self.__class__.__mro__ super(C, self).__init__() class … Read more
The problem is that *ppv is usually a void* – directly assigning this to it will simply take the existing this pointer and give *ppv the value of it (since all pointers can be cast to void*). This is not a problem with single inheritance because with single inheritance the base pointer is always the … Read more