When I moved from ruby to python I found this really annoying: In ruby everything returns something in case you would want it. In python, side-effect methods return void.
I still find it a bit annoying in Python sometimes, but in a language as expressive as #racket, I completely agree with the side that says returning void communicates side-effect.
https://www.mail-archive.com/racket-users@googlegroups.com/msg37825.html