As an occasional R user, I think R markdown one of the things that R does really well. For data scientists who want to output reports (mix of text and calculations), I haven't come across anything as mature or easy to use in the Python ecosystem. I'm a big user of Jupyter notebooks, but version control issues put me off, and I've never got to grips customising the formatting of jupyter nbconvert. It's worth highlight…
Hydrogen for Atom actually can have executable python in markdown, and more - write python in .py files and execute strings or define blocks by "# %%". It's not the same of course but for my usecases it's more convenient (given that it works in a proper code-editor with all needed plugins).