Any idea of a workaround to this warning I get when plotting?
UserWarning: This call to matplotlib.use() has no effect
because the backend has already been chosen;
matplotlib.use() must be called before pylab, matplotlib.pyplot,
or matplotlib.backends is imported for the first time.
problem solved, please ignore
Good. It might in any case be helpful for others (and even for a small correction/improvement) if you share the details in case there is a workaround/solution for an issue. But the important thing is always to get it working.