Clean Code in Python

Extending the events system

Now, let's prove that this design is actually as extensible as we wanted it to be. Imagine that a new requirement arises, and we have to also support events that correspond to transactions that the user executed on the monitored system.

The class diagram for the design has to include such a new event type, as in the following:

Only by adding the code to this new class does the logic keep working as expected:

# openclosed_3.pyclass Event:    def __init__(self, raw_data):        self.raw_data = raw_data    @staticmethod    def meets_condition(event_data: dict):        return Falseclass UnknownEvent(Event): """A type of event that cannot ...