Black interferes with py:percent format in indented code blocks.

I am having an issue where py:percent notebooks that have cells divided within an if statement get destroyed by black when using --pipe black

# %%
if __name__ == '__main__':
     print(1)
# %%
     print(2)

gets reformatted into the following, which is not equivalent

# %%
if __name__ == '__main__':
     print(1)
     # %%
     print(2)

For example, when running the following.

jupytext --to notebook test.py jupytext --to py:percent --pipe black test.ipynb

Will cause all cells that contain only indented code to be merged into one giant cell. Are they any formats / workarounds to ensure black does not destroy the scripts like so? Or are there any relevant settings that jupytext can set that will resolve this issue?

[Skylion007]

@mwouts Yeah, that seems to fix it on my end. At least presuming it rounds trips with --test locally and the outputted notebook appears to be identical.

Here is the example colab btw: https://github.com/facebookresearch/habitat-sim/blob/master/examples/tutorials/colabs/rigid_object_tutorial.ipynb

[Skylion007]

Found another interesting edge case to keep in mind. The following cell works when transferred to colab.

# %%
if __name__ == '__main__':
     print(1)
# %%
     # INDENTED COMMENT
     print(2)

but the following does not:

# %%
if __name__ == '__main__':
     print(1)
# %%
     
     # INDENTED COMMENT
     print(2)

The extra newline at the beginning of the cell seems to reset the indentation of the entire cell. Just something to keep in mind.

JuPyTer and VSCode however don’t seem to care and both cells work fine in both of them. Colab gives an indentation error though.