Named Cursors WITH HOLD

Hi, i'm using psycopg and i'm noticing that Named Cursors are being
deleted by PostgreSQL whenever i do a commit. This is the default
behaviour specified in [1], but there is a parameter when creating a
cursor called "WITH HOLD" that allows a cursor outside any
transaction.

But i can't see any way in the psycopg API to do this. Maybe a cursor
factory, but I've no idea on how to do it.

[1]: http://www.postgresql.org/docs/current/static/sql-declare.html