When launching a jupyter notebook, the environment variableMPLBACKEND is set to inline, but figures will still not be displayed in the output unless%matplotlib inline orimport matplotlib.pyplot is run. Both of these commands hook IPython to a function that gets triggered whenever a Figure is the output from a cell. This function is responsible for printing the figure to the screen.

Proposed solution:

A_repr_html_ method exists for figures, but is only implemented for webagg backends. Something like the following could be added to_repr_html_.

ifrcParams['backend']=='module://ipykernel.pylab.backend_inline':fromioimportBytesIOfrombase64importb64encodepng_bytes=BytesIO()self.canvas.print_figure(png_bytes,format='png')s=png_bytes.getvalue()s1=b64encode(s).decode()returnf'<img src="data:image/png;base64,{s1}"/>'

This is@tacaswell's idea. I previously created an issue with IPython -ipython/ipython#12190 (comment)