Very popular method to declare an abstract method in Python class is to use NotImplentedError exception:

class SomeWorker:
    def do_work(self):
        raise NotImplementedError

This method even has IDE support (I use PyCharm, so at least it supports it).

PyCharm shows an error then I try to inherit without implementing all abstract methods

The only downside of this approach is that you get the error only after method call.

>>> w = MyWorker()
# it's ok
>>> w.do_work()

NotImplementedError

It would be much better to know about the problem right after class instantiation.

Python's abstract base classes are here to help

from abc import ABCMeta, abstractmethod

class SomeWorker(metaclass=ABCMeta):
    @abstractmethod
    def do_work(self):
        pass

For now if you subclass SomeWorker and doesn't override do_work - you will get an error right upon class instantiation

>>> w = MyWorker()
TypeError: Can't instantiate abstract class MyWorker with abstract methods do_work