I have a module I'm writing that uses matplotlib. However, I need it to work with a display(e.g. command-line execution), or when theres no display ( SGE/qsub cluster job, or a cron job).
I found this answer ( Automatic detection of display availability with matplotlib ), which works for the command-line execution and within a cluster job. But, in a cron job, it fails to properly import matplotlib, and seems to throw an exception before I import it.
In the cronjob, I try to import my module with the following script:
import os
os.environ['PYTHONPATH'] = 'path/to/my/module/dir:%s' % os.environ['PYTHONPATH']
print 'now loading mymodule...'
import mymodule
and mymodule.py just has the code from the earlier linked answer:
#!/usr/bin/python
import os
print 'testing import method...'
import matplotlib
r = 0
try :
r = os.system('python -c "import matplotlib.pyplot as plt;plt.figure()"')
except RuntimeError :
pass
print 'r=%d' % r
if r != 0:
print 'matplotlib: running in cluster, using Agg!'
matplotlib.use('Agg')
import matplotlib.pyplot as plt
I get this error message from the cron service:
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/afs/ifh.de/user/u/user/.local/lib/python2.6/site-packages/matplotlib/pyplot.py", line 109, in <module>
_backend_mod, new_figure_manager, draw_if_interactive, _show = pylab_setup()
File "/afs/ifh.de/user/u/user/.local/lib/python2.6/site-packages/matplotlib/backends/__init__.py", line 32, in pylab_setup
globals(),locals(),[backend_name],0)
File "/afs/ifh.de/user/u/user/.local/lib/python2.6/site-packages/matplotlib/backends/backend_gtkagg.py", line 14, in <module>
from matplotlib.backends.backend_gtk import gtk, FigureManagerGTK, FigureCanvasGTK,\
File "/afs/ifh.de/user/u/user/.local/lib/python2.6/site-packages/matplotlib/backends/backend_gtk.py", line 16, in <module>
import gtk; gdk = gtk.gdk
File "/usr/lib64/python2.6/site-packages/gtk-2.0/gtk/__init__.py", line 64, in <module>
_init()
File "/usr/lib64/python2.6/site-packages/gtk-2.0/gtk/__init__.py", line 52, in _init
_gtk.init_check()
RuntimeError: could not open display
now loading mymodule...
testing import method...
r=256
matplotlib: running in cluster, using Agg!
I think its trying and failing to import matplotlib, which is throwing a RuntimeError, before getting to my code in mymodule.py . I can see that it gets to my code and runs it, but the Traceback message makes me nervous.
Why is it loading matplotlib(and crashing) before I tell it to(with Agg)? How can I fix/hide that traceback message?
