[deathanatos]

I went Python → Rust. Rust is high-level enough for me to remain competitively productive with Python, and the type-system just helps so much. I can't tell you how nice it has been to not have to see "Object of type NoneType has no attribute 'foo'" anymore. Also,

  def foo(obj):
    # ...

And me wondering "what is 'obj'?" and then pulling that root … and pulling … and pulling …. Also "data", another just fabulous name for a variable, really narrows the possibilities. Even once you know the "type" of the variable, oftentimes I'd find that the type definition would subtle shift and morph in different parts of the program: they'd all want a Duck, but have varying opinions on what a Duck actually is. You cannot commit such BS with an actual type-checker.

There is more up-front work with the compiler, but it pays off: the code that passes the compiler is of much better quality.

Also, Option<T> is very nice to have when you need an actual Option<T> (i.e., generically), which Python lacks. (No, `None` is not it: You run into problems when T == Option<U>, and you have None and Some(None) — Python's cannot differentiate between the two.) Also sum types in general.

[mr_00ff00]

Right but you essentially just mentioned strong typing. There are a billion languages that don’t run into those issues.

Java, Go, C, Scala, Haskell, etc all fix those type issues.

[deathanatos]

Sure, I suppose, but sum types (which I mention) eliminate all but Scala and Haskell from that list.