Convert code in Frozen Cell as comments in `.py`

[erdnaavlis]

I'm currently test-driving jupytext and I like its potential! Thanks for this neat tool!

I like to use the Freeze Cells extension in my notebooks.
Is it possible to configure jupytext to convert the code in frozen cells as comments in the associated .py file?

[mwouts]

Hello Andre, thanks for suggesting. There is no such option currently. Yet it would be easy to implement support for frozen cells. Would you like to submit a sample notebook with just one frozen cell ? Please send it either by email, or using a PR (put the notebook in tests/notebooks). Thanks!

[erdnaavlis]

Hi @mwouts ,

Thanks for your reply.

Created a PR as you requested containing the notebook and the generated .py with a Frozen Cell.

You will notice in the .py the "run_control": {"frozen": true} part:

# + {"editable": false, "deletable": false, "run_control": {"frozen": true}}
# This is an frozen cell
print("I'm frozen so Im not executed :(")
# -

In such cases, I would like that the code (the print()) to be commented in the .py.

Offtopic:
Since we at it, if you notice the regular cell that I also included in the notebook:

# + {"ExecuteTime": {"start_time": "2018-10-17T10:31:56.157308Z", "end_time": "2018-10-17T10:31:56.160823Z"}}
# This is an unfrozen cell. Works as usual.
print("I'm a regular cell so I run and print!")

It has a ExecuteTime metadata. This is a metadata used by another notebook extension to track when a cell was executed and how long it took.

Would it be possible for the jupytext user to specify which metadata to keep track of and which to ignore?
In my case I don't need this info in the .py and, in fact, I don't want it because it adds noise to git diff...
But maybe other users would like to keep it in the scripts.

Please let me know your thoughts.

[mwouts]

Thanks @andrethrill . The PR will be very helpful to implement and test your initial request - I will try to do that soon.

As for your comment on metadata, I like very much the idea of filtering cell metadata. Would you like to open another issue? As a start we could skip the 'ExecuteTime' cell metadata for everyone (there are already a few cell metadata that jupytext does not include, cf. https://github.com/mwouts/jupytext/blob/master/jupytext/cell_metadata.py#L32). Unless you think it is important that for every notebook, one can tell which cell metadata to include/exclude? Please let me know your preference.