>>>cur.execute("update users set username=%s where id=2",("mypython"))
>>>cur.execute("select * from users where id=2")
>>>cur.fetchone()
>>>conn.commit()
>>>cur.close()
>>>conn.close()
>>>cur.execute("update users set username=%s where id=2",("mypython"))
>>>cur.execute("select * from users where id=2")
>>>cur.fetchone()
>>>conn.commit()
>>>cur.close()
>>>conn.close()