Jupytext should refuse to open out of date paired text representations

Cf. Hari’s question on medium: is it safe to uninstall jupytext ?

Obviously uninstalling is safe. But reinstalling after a while may not be. As text representations have priority over ipynb file, the user that has worked on the ipynb version without jupytext will get the out of date version from the text representation, when he decides to reinstall.

To avoid such a situation (which can be solved by: closing the notebook without saving, and deleting the text file), we should check file timestamps, and refuse to load inputs from text when text seems to be out of date compared to the ipynb file.

[boazbk]

This can also be an issue if one edits the same notebook from different machines, some might have jupytext installed and some might not. I would suggest you put in the meta data of both the ipynb and text file some hash/version number that would be a more reliable way than just looking at the filesystem filestamp. When the ipynb’s version is higher than the textfile’s, it should take precedence. (Or maybe there can be some dialog to ask if they should be merged together or not, if this is feasible.)

[mwouts]

Hi @allenyllee , this is a very old issue so I won’t reopen it, but still I think we can do something for you use case - please see #799.