Hi,
I’m having a problem when importing pylab in a python CGI script to generate some dynamic graphs for a web page.
As soon as I import pylab, my script will fail, and I have no idea why.
As an example, i can have 1x1 black png file, loaded from a script like thus:
#!/usr/bin/env python
black.py
fh = open(‘black.png’)
print “Content-type: image/png\n”
print fh.read()
And called from a HTML page via:
This will work perfectly until i modify the script to:
#!/usr/bin/env python
black.py
import pylab
fh = open(‘black.png’)
print “Content-type: image/png\n”
print fh.read()
And I have no idea why
I’m fairly new to HTML, and I can’t seem to see any meaningful errors in Firebug. Anyone have any experience with an error like this?
The script runs fine from a terminal and outputs as expected.
I’m using python2.4, python-matplotlib-0.91.2-1.el5.rf on Centos 5.3 (old I know, but this is a production server)
Any help would be much appreciated.
Hi Sandro,
Thanks for the tip.
In checking the HTTP logs, I found that the apache user couldn’t create a “.matplotlib” directory (as it had no home dir) so i used the environment variable MPLCONFIGDIR to point to somewhere meaningful, then I found that to “import pylab” I needed a DISPLAY variable etc, etc, and I’ve eventually got everything working as expected by importing like thus:
import os
os.environ[‘MPLCONFIGDIR’]=‘/path/for/.matplotlib’
import matplotlib
matplotlib.use(‘Agg’)
import matplotlib.pyplot as plt
Found this too, I should have RTFM
http://matplotlib.sourceforge.net/faq/howto_faq.html#howto-webapp
Cheers,
Mark
···
On Tue, Jun 1, 2010 at 4:44 PM, Sandro Tosi <morph@…10…> wrote:
Hello Mark,
On Tue, Jun 1, 2010 at 08:17, Mark Boorer <markboo99@…287…> wrote:
And I have no idea why
I’m fairly new to HTML, and I can’t seem to see any meaningful errors in
Firebug. Anyone have any experience with an error like this?
This is not HTML, it’s a CGi, so a script executed server-side; to
know what’s going wrong, check the log files of your web server.
Regards,
–
Sandro Tosi (aka morph, morpheus, matrixhasu)
My website: http://matrixhasu.altervista.org/
Me at Debian: http://wiki.debian.org/SandroTosi