The Jupyter notebook .ipynb document format combines markdown text, code, and code outputs (embedded images, data tables) inside a JSON document structure.

Spelling checking notebooks with cleared output cells generally works fine, but in some workflows it may be more convenient to spell check run notebooks. However, testing cell outputs may generate a large number of essentially false positive spelling errors.

It would be useful to be able to invoke a codespell switch (for example, --ipynb) that would ensure that only cell inputs are spell checked. (The nbformat package provides a parser that can be used to parse notebooks.)

Notebook cells may also include cell tag metadata. It might also be useful to be able to specify cell tags to control the spell checking at both cell input and output level. For example:

• codespell-ignore: ignore this cell;
• codespell-check-output: also check the output of this (code) cell.