Incompatibility with python3-pil v7.0

[Nicolas Moriniere]

I am using Ubuntu 20.04.1 LTS (including python3-matplotlib 3.1.2-1ubuntu4)

To save a figure using matplotlib.pyplot into a jpg file, matplotlib uses Python Imaging Library (PIL). Unfortunately even if we install the package python3-pil 7.0.0-4ubuntu0.1 it fails:

File "/usr/lib/python3/dist-packages/matplotlib/backend_bases.py", line 1961, in _get_output_canvas
        raise ValueError(
    ValueError: Format 'jpg' is not supported (supported formats: eps, pdf, pgf, png, ps, raw, rgba, svg, svgz)

The reason is matplotlib detect PIL version by doing so (in file backend_bases.py line 57):
from PIL import PILLOW_VERSION

PILLOW_VERSION has been removed since PIL version 7.0 to be replaced by PIL.__version__

To solve this issue it seems that you have to upgrade python3-matplotlib package at least to version 3.3 (the version packaged for ubuntu 20.10, I think)

[Satoru Takeuchi (satoru-takeuchi)]

I encountered the same problem.

> To solve this issue it seems that you have to upgrade python3-matplotlib package at least to version 3.3 (the version packaged for ubuntu 20.10, I think)

v3.1.3 also supports pillow >= 7.0. This version might be more appropriate.

https://github.com/matplotlib/matplotlib/releases/tag/v3.1.3
> - support pillow >= 7

Original fix.
https://github.com/matplotlib/matplotlib/pull/16086

This fix is applied to v3.1.3
https://github.com/matplotlib/matplotlib/blob/v3.1.3/lib/matplotlib/backend_bases.py#L57