Python Headless MatplotLib / Pyplot [duplicate]

Answer 1

Turns out a utility file (not mine!) was pulling in pylab for something else. Shifted the matplotlib backend selection into the initial page.

Answer 2

Try importing matplotlib and setting the Agg backend before importing numpy:

import matplotlib
matplotlib.use("Agg")

Answer 3

Everything you describe sounds correct. What happens when you run this:

import matplotlib
matplotlib.use('Agg')
import pylab
pylab.plot([1,2], [3,4], linestyle='-')
pylab.savefig('foo.png')

In my environment it produces this (I scaled it down):