Numpy and Matplotlib on Google App Engine

#!/usr/bin/python
import logging, os, StringIO, cgi
try: import webapp2
except: pass  # when ran directly from command line
import subprocess
def no_popen(*args, **kwargs): raise OSError("forbjudet")
subprocess.Popen = no_popen  # not allowed in GAE, missing from module
subprocess.PIPE = None
subprocess.STDOUT = None
os.environ["MATPLOTLIBDATA"] = os.getcwdu()  # own matplotlib data
os.environ["MPLCONFIGDIR"] = os.getcwdu()    # own matplotlibrc
import numpy, matplotlib, matplotlib.pyplot as plt

def dynamic_png():
    try:
        plt.title("Dynamic PNG")
        for i in range(5): plt.plot(sorted(numpy.random.randn(25)))
        rv = StringIO.StringIO()
        plt.savefig(rv, format="png")
        plt.clf()
        return """<img src="data:image/png;base64,%s"/>""" % rv.getvalue().encode("base64").strip()
    finally:
        plt.clf()


def dynamic_svg():
    try:
        plt.title("Dynamic SVG")
        for i in range(5): plt.plot(sorted(numpy.random.randn(25)))
        rv = StringIO.StringIO()
        plt.savefig(rv, format="svg")
        return rv.getvalue().partition("-->")[-1]
    finally:
        plt.clf()

try: dynamic_png()  # crashes first time because it can't cache fonts
except: logging.exception("don't about it")

if __name__ != "__main__":
    class MainHandler(webapp2.RequestHandler):
        def get(self):
            self.response.write("""<html><head><title>Numpy and Matplotlib on Google App Engine</title></head><body>""")
            self.response.write(dynamic_png())
            self.response.write(dynamic_svg())
            self.response.write("<pre>%s</pre>" % cgi.escape(file(__file__.rstrip("c")).read()))  # source, dev runs .py, gae runs .pyc
            self.response.write("""</body> </html>""")

    app = webapp2.WSGIApplication([
        ('/', MainHandler)
    ], debug=True)