By properly utilizing Algebraic Data Types (ADTs, not to be confused with abstract data types), you can transform certain types of invalid states from runtime errors into type-checking errors, making them an excellent method for representing data and managing state. Although ADTs may sound complex, they represent a fairly straightforward concept. They are composite types, meaning they reference or contain other types, and primarily consist of two basic categories: product and sum types. If you have experience with tuples, youve worked with product types, and if youve used booleans, youve dealt with sum types. While there are additional types, well focus on these two fundamental categories for now. Product types include tuples, named tuples, dataclasses, attrs classes, msgspec classes, TypedDicts, and more. Sum types include bool, enums, literals, and unions. This article explores the various types of ADTs and how to use them effectively in typed Python code.
