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Using the recent ipykernel 7.x causes plots to not show up from ipympl widgets.

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
48/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Quiet
Tech stack
jupyter, matplotlib, python

Research direction

Start with the linked ipympl issue 609 and review the ipykernel 7 matplotlib-related changes mentioned in the report. Reproduce the behavior with recent jupyterlab, ipympl, and ipykernel versions on the reported platforms, compare against ipykernel 6.3.1, and verify that ipympl plots display without an explicit plt.show().

Written by the indexing model from the issue text.

Description

After upgrading to recent versions of jupyterlab, ipympl and ipykernel I observed on different systems, either Windows 11 or Linux, that ipympl figures would not show up sometimes without an explicit plt.show() at the end of the cell.

While this looked to me at first glance like an ipympl bug because it does not appear using inline figures it turns out that downgrading ipykernel to 6.3.1 completely solves the issue.

Here is the the original report with more details: https://github.com/matplotlib/ipympl/issues/609

I saw that ipykernel>=7 has quite a few changes regarding matplotlib, so I assume this is a unwanted side-effect of these changes.

Dominant language
Python
Stars
734
Forks
411
Avg merge
1d 2h
Merged PRs (30d)
9

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