> Doesn't it just require you to express the interface you're already using and expecting to use? Depends on the type system. Some type systems have a lot of c

> Doesn't it just require you to express the interface you're already using and expecting to use? Depends on the type system. Some type systems have a lot of ceremony around types and force you into contrived abstractions. For instance, in Scala, if you wanted to have a function that can print a name of an animal or person, you could overload the function, create a "nameable" trait and have both Person and Animal implement it, or create a union type. In typescript you could just write sayHello(thing: {name: string}) { ... } or a union type sayHello(thing: Person | Animal) or even Pick out a group of parameters of both Person and Animal sayHello(thing: Pick<Person | Animal, "name">) Same with Omit Types in typescript are incredibly flexible and useful despite being discarded at compile time. I hope python goes down this route.