I find that code that uses dictionaries a lot ends up with mysterious unnamed types used in various places throughout the system disguised as dictionaries. They

I find that code that uses dictionaries a lot ends up with mysterious unnamed types used in various places throughout the system disguised as dictionaries. They have required fields, and must interacted with using business logic that is not obvious. This becomes a real problem when the original authors of the system are gone, and new maintainers have taken over and have to implement new features. By using objects, or lightweight objects like namedtuple, which have already been mentioned in other comments a bunch, you formally document the data-structure. You give it a name, expected fields, and required behaviours when interacting with it. The code becomes much easier to follow and understand clearly. Bugs don't creep in when a new maintainer forgets about the mysterious undocumented required business logic.