executing a sql script

I'm using python and can execute standard "select,update,delete,functions".
What I'd like to do is execute a sql script (a text file).  But I don't know
how?
Some thing like:
 import psycopg2
 import psycopg2.extensions
        conn = psycopg2.connect("host=%s dbname=%s user =%s  password
=%s " %(self.pgSqlHostID.Value,self.pgSqlDatabaseID.Value,self.pgSqlUserID.Value,self.msSqlPasswordID.Value))

conn.set_isolation_level(psycopg2.extensions.ISOLATION_LEVEL_AUTOCOMMIT)
        tempCursor= conn.cursor()
        try:
            tempCursor.execute("run script %s " % FileNameScript)
            tempCursor.execute('commit')
--
John Fabiani