For the Python in markdown case, you might be interested in one of my projects that allows executable Python code (including optional Jupyter kernel support) in

For the Python in markdown case, you might be interested in one of my projects that allows executable Python code (including optional Jupyter kernel support) in Pandoc markdown: https://github.com/gpoore/codebraid https://github.com/gpoore/codebraid. Pandoc does all the document parsing (there is no regex preprocessor for extracting code), so converting markdown to markdown often works particularly well.