Bug report

Bug summary

Usingipywidgets.interact to update a figure works as expected inmatplotlib<=3.3.1, but fails inmatplotlib==3.3.2.

I don't think this is anipywidgets issue since downgradingmatplotlib fixes this issue.

Code for reproduction

In[1]:

%matplotlibnotebookimportmatplotlibasmplimportmatplotlib.pyplotaspltimportipywidgetsasipyw"works if %s <= 3.3.1"%mpl.__version__

In[2]:

fig=plt.figure()@ipyw.interact(m=ipyw.FloatSlider(value=1,min=-10,max=10,step=0.01))defupdate(m):plt.figure(fig.number,clear=True)plt.plot([m*xforxinrange(-9,10)])

Followed by moving the slider.

Actual outcome

• when moving the slider, the figure does not update
• a second figure is sometimes created instead
• the second figure is usually blank, but sometimes updates instead

Expected outcome

• the original figure updates as it does inmatplotlib==3.3.1

Matplotlib version

• Operating system: Ubuntu
• Matplotlib version: 3.3.2 vs 3.3.1
• Matplotlib backend (print(matplotlib.get_backend())): nbAgg
• Python version: 3.7.8
• Jupyter version (if applicable): jupyter-core==4.6.3
• Other libraries: ipywidgets==7.5.1
• Installation source:conda channelconda-forge