[randtrain34]

But suppose you were unfamiliar with the code, the 2nd tells you what fields/methods are available for "item", and furthermore most IDEs will use that info to populate autocomplete suggestions and such.

[falcolas]

Language engines exist for Python and Ruby (and Lisp, etc.)as well, and they handle autocomplete and refactoring quite handily.

[maleldil]

How would a "language engine" know what you can do with `item` if it has no type information?

You can do that with Python (sometimes) because many libraries have type hints today, so even if you don't use types yourself, the type checker can infer them in your code and help you out.

[semiquaver]

No they don’t.