Plotting using matplotlib from PyPy

Big fat warning This is just a proof of concept. It barely works. There are missing pieces left and right, which were replaced with hacks so I can get this to run and prove it's possible. Don't try this at home, especially your home. You have been warned.

There has been a lot of talking about PyPy not integrating well with the current scientific Python ecosystem, and numpypy (a NumPy reimplementation on top of pypy) was dubbed "a fancy array library". I'm going to show that integration with this ecosystem is possible with our design.

First, the demo:

#!/usr/bin/env pypy

# numpy, pypy version
import numpypy as numpy
# DRAGONS LIVE THERE (fortunately hidden)
from embed.emb import import_mod

pylab = import_mod('matplotlib.pylab')

if __name__ == '__main__':
    a = numpy.arange(100, dtype=int)
    b = numpy.sin(a)
    pylab.plot(a, b)
    pylab.show()

And you get:

Now, how to reproduce it:

• You need a PyPy without cpyext, I did not find a linker that would support overriding symbols. Right now there are no nightlies like this, so you have to compile it yourself, like:

  ./translate.py -Ojit targetpypystandalone.py --withoutmod-cpyext
  

  That would give you a PyPy that's unable to load some libraries like PIL, but perfectly working otherwise.

• Speaking of which, you need a reasonably recent PyPy.

• The approach is generally portable, however the implementation has been tested only on 64bit linux. Few tweaks might be required.

• You need to install python2.6, the python2.6 development headers, and have numpy and matplotlib installed on that python.

• You need a checkout of my hacks directory and put embedded on your PYTHONPATH, your pypy checkout also has to be on the PYTHONPATH.