PostgreSQL – how to run VACUUM from code outside transaction block?

After more searching I have discovered the isolation_level property of the psycopg2 connection object. It turns out that changing this to 0 will move you out of a transaction block. Changing the vacuum method of the above class to the following solves it. Note that I also set the isolation level back to what it previously was just in case (seems to be 1 by default).

def vacuum(self):
    old_isolation_level = self.conn.isolation_level
    self.conn.set_isolation_level(0)
    query = "VACUUM FULL"
    self._doQuery(query)
    self.conn.set_isolation_level(old_isolation_level)

This article (near the end on that page) provides a brief explanation of isolation levels in this context.