Matplotlib Hangs In Django

I'm trying to draw some charts generated by Matplotlib but I am finding that whilst it works correctly the first time, if I refresh my page, Matplotlib will just hang on _tkinter.c

Solution 1:

The issue turned out to be an issue with using the wrong backend... The issue was resolved with jenshnielsen's suggestion to change the backend that is being used before importing pyplot

import matplotlib
matplotlib.use('agg')

_{If your reading this, Jens, please post your own answer and I'll gladly delete this one!}