Python create instance of derived class

I want to have abstract class Task and some derived classes like TaskA, TaskB, ... I need static method in Task fetching all the tasks and returning list of them. But problem is that I have to fetch every task differently. I want Task to be universal so when I create new class for example TaskC it should work without changing class Task. Which design pattern should I use? Let's say every derived Task will have decorator with its unique id, I am looking for function that would find class by id and create instance of it. How to do it in python?