Matplotlib has a problem finding a backend after I use pyinstaller

Question

I'm trying to make an .exe file from .py and I'm having an issue with matplotlib library. When I run my script in VS Code plt.show() works just fine. But when I use pyinstaller to make an .exe and run the .exe file, it gives me a following warning: "UserWarning: Matplotlib is currently using agg, which is a non-GUI backend, so cannot show the figure." Importing TkAgg directly with "import matplotlib.backends.backend_tkagg" doesn't solve the problem either. Is it possible to fix that?

Answer 1

I ran into the same issue.

I found this article, which may be helpful: "UserWarning: Matplotlib is currently using agg, which is a non-GUI backend, so cannot show the figure." when plotting figure with pyplot on Pycharm

However, the simple fix in my case was to just explicitly import the backend module(s):

import matplotlib.backends.backend_tkagg
import matplotlib.backends.backend_wxagg

Pyinstaller does some relatively sophisticated analysis and Matplotlib itself has some relatively sophisticated code to be able to use multiple GUI backends. I think the overall problem is that Pyinstaller isn't seeing that any particular backend is actually being used and so doesn't end up bundling any backend module.

Explicitly making the import makes it obvious to Pyinstaller that you want that module (importing it is effectively using it). (Maybe you only need the one for 'tkagg' - I happen to be working with a WX GUI, so I included both imports - it works.)