For those of us that don't use Lisp (or Emacs+SLIME), and are stuck with Python/Julia/Lua/etc and Vim may I give a practical recommendation? The Vim-Slime plugin [1] is a half-decent way of making interactive development work. With a bit of tuning you can make it start a terminal emulator window inside Vim, and have it send the current paragraph of your source code into it with a press of a button.
While not as great as working with a proper Repl-oriented language (as the article explains), this is still so much more pleasant than having to re-run the whole program every time you change a function.
While not as great as working with a proper Repl-oriented language (as the article explains), this is still so much more pleasant than having to re-run the whole program every time you change a function.
[1] https://github.com/jpalardy/vim-slime