> There’s nothing to stop calling functions with incorrect datatypes at runtime You can enforce typechecking of your code on the CI with a tool like `mypy` if

> There’s nothing to stop calling functions with incorrect datatypes at runtime You can enforce typechecking of your code on the CI with a tool like `mypy` if you want additional safety. But you'll never get the same guarantees you'd get in OCaml or Rust. It's a tradeoff between flexibility and safety.