[SQLObject] Connection errors

Hello,
        I have a question related with the connections. I am using the
following code for that:

try:
     connection = connectionForURI('postgres://'+user+':'+password+'@
'+host+'/'+database)
     sqlhub.processConnection = connection
     connection.query("SELECT 1")
except OperationalError:
     print "error"

but, I don't know if the error is because the user and password are wrong
or the sever is not working. How can I verify that? for example, maybe,
with a error code but I don't know how to get it.

Cheers,