How to switch backends in matplotlib / Python

Question

Hi,

I am struggling with the following issue. I need to generate reports that consists of a collection of charts. All these charts, except one, are made using Matplotlib default backend (TkAgg). One chart needs to be made using the Cairo backend, the reason is that I am plotting an igraph graph and that can only be plotted using Cairo.

The issue is that I cannot change backends on the fly, for example the following does not work:
matplotlib.pyplot.switch_backend('cairo.png') (I know that the switch_backend functionality is experimental)

and I have also tried matplotlib.use("cairo.png") but this leads to import problems as the matplotlib.use("cairo.png") statement should come before importing matplotlib.pyplot. but I need two different backends over the course of the life of the script.

So my question is does someone have a code snippet that shows how to switch the backend in Matplotlib?

Thanks so much!

UPDATE: I have written a snippet that loads matplotlib, shows the default backend, unloads matplotlib, reloads it and changes the backend:

import matplotlib
import matplotlib.pyplot as plt
import sys
print matplotlib.pyplot.get_backend()

modules = []
for module in sys.modules:
    if module.startswith('matplotlib'):
        modules.append(module)

for module in modules:
    sys.modules.pop(module)

import matplotlib
matplotlib.use("cairo.png")
import matplotlib.pyplot as plt

print matplotlib.pyplot.get_backend()

but is this really the way to do it?

UPDATE 2: I had some serious brain freeze yesterday... The simple and most obvious solution is to use the Cairo backend for all charts and not to switch the backend at all :)

UPDATE 3: Actually, it's still an issue so anybody who knows how to dynamically switch matplotlib backends....please post your answer.

Answer 1

So I am not completely sure if this is what you are looking for.

You can change your backend through the matplotlibrc file which contains certain configurations for your matplotlib.

In your script you can put:

matplotlib.rcParams['backend'] = 'TkAgg' 

or something like that to switch between backends.