There is no such thing as "standard patterns". There are a large number of different popular patterns which many developers have found useful for a broad range of uses.
Don't get too hung up on the implementation details in any particular language. A Python function that returns a class is just a factory by another name. The essential point is deferring the decision of which implementation class to instantiate until run time.
Inheritance is one way of handling abstract APIs, but not the only way (depending on language). And don't believe everything you read on the Internet. In some limited circumstances inheritance can be a great way to simply code and eliminate duplication, far outweighing any additional complexity it introduces.
Don't get too hung up on the implementation details in any particular language. A Python function that returns a class is just a factory by another name. The essential point is deferring the decision of which implementation class to instantiate until run time.
Inheritance is one way of handling abstract APIs, but not the only way (depending on language). And don't believe everything you read on the Internet. In some limited circumstances inheritance can be a great way to simply code and eliminate duplication, far outweighing any additional complexity it introduces.