Run R or Python right here in your browser. Nothing to install: pick a language and a starter, edit the code, press Run. The first run takes a little while to load the language; after that it is quick.
Your code stays in this browser tab. To keep it, copy it into RStudio or your own Python file. In RStudio you can load the full course helpers with source("functions/..."); the playground defines only the few functions each starter uses, so it loads fast.