The biggest selling point of Crystal is being a very high level language, but at the same time very performant. Think of a Ruby variant with Go speed.
I would like to have something similar for Python.
I would like to have something similar for Python.
Also, the FFI in Nim is basically just declaring some C function as a `proc`. So, wrapping existing C libraries is as easy as Cython for Python. You can even jump start things by running `c2nim` on a header file.
I know there are a few different protobuf impls floating around. Not sure how much google pubsub needs beyond that. It's probably not so far away. Maybe you can be the one to do the pubsub wrapper. :-) (I'm only trying to encourage, not enlist/conscript.)
Depending on the application, F# is a fantastic alternative to Python if you want some succinct code (with advanced types too) and fast runtime performance.
For anything 'scientific' there is Julia (with PyCall and RCall).
That said, it's a completely different language from Python, so the comparison to Ruby/Crystal is not very apt.