OWA (Outlook Web Access) with urllib2

[Pascal]

Effectively, if you look at http://python.org/2.4/NEWS.html you can
see that
urllib2 now recognizes Basic authentication even if other
authentication schemes are offered.

In LiveHTTPheaders/Firefox debug, there is
 WWW-Authenticate: Negotiate
 WWW-Authenticate: NTLM
 WWW-Authenticate: Basic realm="owa.mydomain"
and the basic authentification is the last proposed.

So now, how can I force basic authentification with urllib2 (without
using Python 2.4a)?