Better handling of cells that contain string 'nbdev_export('

[ozpau]

Currently, if you just happen to include string nbdev_export( in your code cell, the whole cell will be silently ignored by nbdev_prepare, nbdev_test, nbdev_proc_nbs and nbdev_preview. If this cell happens to contain code that is exported or rendered in docs, it would result in the corresponding command failing with hard to decipher error.

I have removed the corresponding check from the nbdev code. I am not sure we need it, but I can make a version of this pull request that handles that more gracefully by injecting monkey patching code into notebooks, something like this:

k.run_cell('import nbdev\ndef noop(*args, **kw): pass\nnbdev.nbdev_export = noop')

I imagine the check was there to prevent infinite loops of nbdev_prepare calling itself, but this doesn't happen because the check is for nbdev_export and not for nbdev_prepare.

[hamelsmu]

Can you give me an example use case where you need to have the string nbdev_export() in a code cell ? Is this something that is blocking you or more theoretical?

cc: @jph00

[ozpau]

I have stumbled upon this while creating a tool to generate notebook from a template. https://github.com/ozpau/oztools/blob/main/nbs/api/02_nbd.ipynb see new_notebook_template.

It's not a blocker, since there's a simple solution to instead write something like 'nbdev.nbdev_e'+'xport()' in the code cell (and that's what nbdev uses internally).

But it was confusing at first because my notebook run, but exported code was wrong.