Unable to read WSDL file from ONVIF

[wari]

I've just tried the following with Python 2.7.9

>>> from SOAPpy import WSDL
>>> wsdl = 'http://www.onvif.org/ver10/media/wsdl/media.wsdl'
>>> server = WSDL.Proxy(wsdl)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.7/site-packages/SOAPpy/WSDL.py", line 91, in __init__
    service = self.wsdl.services[0]
  File "/usr/lib/python2.7/site-packages/wstools/Utility.py", line 1184, in __getitem__
    return self.list[key]
IndexError: list index out of range

I'm not sure what's happening here.