Unfortunately, you can’t do exactly what you want. You can do this with interfaces though: public interface IInterface { string MyProperty { get; } } public class Class : IInterface { public string MyProperty { get; set; } } The way I would do it is to have a separate SetProperty method in the concrete … Read more
Traits allow you to share code between your classes without forcing you into a specific class hierarchy. Say you want all your classes to have the convenient utility method foo($bar); without traits you have two choices: implement it individually with code redundancy in each class inherit from a common (abstract) ancestor class Both solution aren’t … Read more
There is no direct compiler-enforced way to do this, as far as I know. You could work around it by not making the parent class instantiable, but instead providing a factory method that creates an instance of some (possible private) subclass that has the default implementation: public abstract class Base { public static Base create() … Read more
Whether a method is implemented using async/await or not is an implementation detail. How the method should behave is a contract detail, which should be specified in the normal way. Note that if you make the method return a Task or a Task<T>, it’s more obvious that it’s meant to be asynchronous, and will probably … Read more
The practical side of abstract classes is that you can encapsulate a part of implementation that works with the state, so that it cannot be overridden in the derived classes. In an interface, you can only define a property without a backing field, and an implementation class must override that property (with either a backing … Read more
Both methods can be used to customize the result of the issubclass() built-in function. __subclasscheck__ class.__subclasscheck__(self, subclass) Return true if subclass should be considered a (direct or indirect) subclass of class. If defined, called to implement issubclass(subclass, class). Note that these methods are looked up on the type (metaclass) of a class. They cannot be … Read more
Abstract Abstract Classes focus on a kind of things similarity. People are considered of type mammal and as such would not be considered of type vehicle. Interface Interfaces focus on collation of similar function. For example: You are a human being and are of type mammal. If you want to fly then you will need … Read more
At its root, this is part of the mismatch between objects and relational databases. The ORM does a great job in abstracting out the differences, but sometimes you just come up against them anyway. Basically, you have to choose between abstract inheritance, in which case there is no database relationship between the two classes, or … Read more
You cannot have an abstract constructor because abstract means you must override it in any non-abstract child class and you cannot override a constructor. If you think about it, this makes sense, since you always call the constructor of the child class (with the new operator) and never the base class. Generally speaking, the only … Read more
I know the basic use of abstract classes is to create templates for future classes. But are there any more uses of them? Not only can you define a template for children, but Abstract Classes offer the added benefit of letting you define the functionality that your child classes can utilize later. You could not … Read more