Python 17th Day Abstract class

1  fromAbcImportAbcmeta, Abstractmethod2 3 classA (metaclass=Abcmeta): called a abstract class4 @abstractmethod5     defTest (self):Pass test is an abstract method and must be implemented by an inherited subclass6 7 8 classB (A):9     PassTen  OneB () If you create an object of Class B, you will get an error.

Typeerror:can ' t instantiate abstract class B with abstract methods test

Python3, later, new class, multiple inheritance, method lookup order, breadth first algorithm

1 classA:2     defTest (self):3         Print('In A')4 5 classB (A):6     defTest (self):7         Print('In B')8 super (). Test ()9 Ten classC (A): One     defTest (self): A         Print('In C') - super (). Test () -  the classD (B): -     defTest (self): -         Print('In D') - super (). Test () +  - classE (C): +     defTest (self): A         Print('In E') at super (). Test () -  - classF (D, E): -     defTest (self): -         Print('In F') - super (). Test () in  -  to F (). Test () +  - Print(F.mro ())

Execution results

inchFinchDinchBinchEinchCincha[<class '__main__. F', <class '__main__. D', <class '__main__. B', <class '__main__. E', <class '__main__. C', <class '__main__. A', <class 'Object';]

Python 17th Day Abstract class