Clean Code in Python

Chain of responsibility

Now we are going to take another look at our event systems. We want to parse information about the events that happened on the system from the log lines (text files, dumped from our HTTP application server, for example), and we want to extract this information in a convenient way.

In our previous implementation, we achieved an interesting solution that was compliant with the open/closed principle and relied on the use of the __subclasses__() magic method to discover all possible event types and process the data with the right event, resolving the responsibility through a method encapsulated on each class.

This solution worked for our purposes, and it was quite extensible, but as we'll see, this design pattern will ...