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Comment by petters | Hacker News Reader

Defining the same variable more than once is an error. The reason for this is obvious. But if the variable is never used in a cell that does not first write to it, reusing variable name should be possible.

Allowing that would be good, because many notebook cells start with "fig, ax = plt.subplots(2, 2)" and this is currently not allowed more than once.

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Does the local underscore variables feature solve this? Or the approach outlined in the plots tutorial? IMO, not allowing redeclaration is more valuable than supporting this use case. A slight paradigm shift away from your example gives you the significant benefits of a reactive environment with fewer edge cases/quirks. I'd much rather have a notebook error out instead of silently overwriting a value. You save so much time debugging.

> Does the local underscore variables feature solve this

I tried this yesterday trying to convert a Jupyter notebook with a log of fig, axs, and it was very annoying converting all of them. I tried local _ with fig_ and ax1_ …etc. but it is considered a variable that cannot be reused too. Furthermore, I expected local vs global variables to be cell based somehow, but that was naive on my part. It does static analysis, not dynamic, so defining something like _suffix and add it to all reused variables and assign different values for each cell will need a dynamical analysis to work.

Yes, but what I proposed seems like no risk of silently overwriting? If there are dependencies between cells there will still be an error

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