Not everyone uses matplotlib inside of scripts! Judging from the
manual, this is the only approved way to use the library.
There seems to be no way to change the backend in the middle of an
interactive session. Looking through the manual, I find that I can
specify it on the command line, in .matplotlibrc, or via
matplotlib.use('..'), but only "before you import matplotlib.pylab"
I would be extremely happy if there were a way to change backends
midstream from an interactive shell (I use ipython, for example)