I use Python for machine learning, but I wish I could use a friendly, modern, statically-typed language like Kotlin, Swift, etc. instead. Dynamically typed languages feel scary beyond around 1000 lines of code.
+1, I recently wrote some data extraction and processing code using pandas and mypy, and it was pretty great. And progress is happening to add types to numpy and pandas themselves.
The downside is that static typing makes your programs much more rigid. Even if you program to interfaces, apply open-closed principle etc. After a while you start fighting the type system.
That's why I like dynamic typing. Coupled with Python's type annotations for hard cases and good documentation, dynamic typing allows you to go further by reducing cognitive load.