How do I reset the Jupyter/IPython input prompt numbering?

Question

I just wrote my first extensive Python tutorial using IPython notebooks. All went well, except I did a lot of testing and moving blocks around. How do I reset the In [

Answer 1

For those coming from Google:

%reset

This is useful when you want to reset all variables after a certain point in the notebook. It is going to ask if you are sure that you want to reset. If you want to force reset without asking, then use:

%reset -f

Answer 2

I think, the only way to to what you want is: - 'Kernel > Restart' (restart the kernel) and then 'Cell > Run All' (run the script).

Answer 3

If what you want is to remove the numbers themselves, so that each cell shows In [ ] (instead of something like In [247] which is leftover from some previous incarnation of the kernel), use "Cell" > "All Output" > "Clear" (in Jupyter Notebook 5.4.0) or "Edit" > "Clear All Outputs" (In Jupyter Lab 0.32.1).

This will remove all the numbers, even if you're in the middle of running a notebook. It will not reset the numbering back to 1; e.g. if the last cell you executed was 18, the next will be 19.

If you're using this because you want clarity about which cells you've executed during this run of the kernel and which cells you haven't executed yet, use "Cell" > "All Output" > "Clear" (or "Edit" > "Clear All Outputs") immediately after you start (or restart) the kernel. This can be useful when restarting a kernel, or when opening a saved or duplicated notebook.

This will also remove all outputs from the notebook.

Thanks to user2651084 in a previous comment for this.