Is there a list of which formats offer roundtripping ?

I tried jupytext initially, with .py, but I noticed, when roundtripping to ipynb, that multiple newlines can result in code cells splitting up.

Now I’m trying .md, as I could see this in github, though it turns out to be not completely ideal as github shows all the metadata at the top.

What is the best format to use that can handle a round trip ?

[mwouts]

That looks good, is there a list that maps extensions to the format names somewhere ?

That’s a good idea! I’ll update the PR. Basically,

• the .md extension corresponds to either the markdown (default) or pandoc formats (calls pandoc, so you should have a recent version of pandoc installed)
• the .Rmd extension corresponds to the rmarkdown format (default)
• the script formats uses the language extension, i.e. .py in the context of a Python notebook. And the available formats are light (the default), percent (# %% markers), sphinx (if you are using sphinx-gallery, cannot store cell metadata), hydrogen (same as percent, except that magic commands are not commented out), and nomarker (no cell marker nor metadata, obviously not robust to a round trip).

[mwouts]

Hello @stuaxo , thanks for asking.

The three main formats, i.e. py:percent, py:light and md should be robust to the round-trip. Now the question is how you define the cells: py:percent is the most explicit with # %% before every cell, the two others may indeed use single or double blank lines as cell breaks.

These formats are documented here.

Given a text file, or an .ipynb notebook, you can test the round-trip with

jupytext --to ipynb --test script.py # or --test-strict

as github shows all the metadata at the top

For this, you can give a try to the notebook metadata filter. Uncheck the ‘include metadata’ entry in the Jupytext menu, or execute:

jupytext --update-metadata '{"jupytext": {"notebook_metadata_filter":"-all"}}' notebook.ipynb