How to undo/redo changes inside the selected cell in Jupyter notebook?

Question

I am using Jupyter notebook (from anaconda Jupyter lab) on Windows 10 and tried to undo/redo changes in the selected cell. However, I can only undo/redo changes in the whole notebook.

For example, I edited cell#1 then cell#2. Say I want to undo changes in cell#1, so I go to cell#1 and press control+z, it will however undo the change in cell#2.

My friend using Mac doesn't have this issue. Are there any settings for this? I searched online and didn't find anyone who has the same problem. It is so weird!

Answer 1

This global undo/redo is a new feature that enables Real Time Collaboration which was added in JupyterLab 3.1. It is indeed sub-optimal for many use cases.

JupyterLab 3.2 allows to disable notebook-wide history tracking (see issue 10791 nad PR 10949), but with a caveat: when moving cells you may loose the undo history, which is why the setting is marked as experimental (it requires more work to be exposed or enabled by a default). To get the selective undo/redo please add:

{
    "experimentalDisableDocumentWideUndoRedo": true
}

in Advanced Settings Editor → Notebook, save, and reload JupyterLab (if you use it in a browser a refresh should suffice).

You can also stick with JupyterLab 3.0 if this is a deal breaker. To downgrade you can use pip:

pip install "jupyterlab<3.1"

or conda:

conda install -c conda-forge "jupyterlab<3.1"

but I would recommend sticking with JupyterLab 3.2 and trying out the new setting so you can contribute to the discussion (if you experience any problems or believe it could be improved).