我真的不明白元組是如何工作的。但我所知道的是它們看起來像這樣。    (1, variable)但我不斷收到錯誤：Python type tuple cannot be converted有人可以幫忙嗎這是我的代碼：    @client.command()async def buy(ctx, item: str):    USER_ID = ctx.message.author.id    write_log("Buy command requested")    #write_log("Sending GET request to Cosmos API...")    try:        SQL.execute("SELECT price FROM shop WHERE itemname = %s", (item,))        price = SQL.fetchone()        SQL.execute("SELECT balance FROM Accounts WHERE user_id = %s", (USER_ID,))        SQL.execute("UPDATE Accounts SET balance = balance - %s WHERE user_id = %s", (price, USER_ID))        db.commit()        await ctx.send(f"Successfully bought **{item}** for **{price} Rollars**.")    except Exception as ex:        write_log('ERROR')        full_traceback = traceback.format_exc()        write_log(f'Errored whilst sending ctx(embed), (about): {ex} {full_traceback}')完整的回溯：Traceback (most recent call last):  File "Bot.py", line 316, in buy    SQL.execute("UPDATE Accounts SET balance = balance - %s WHERE user_id = %s", (price, USER_ID))  File "/home/vihanga/lib/python3.8/site-packages/mysql/connector/cursor_cext.py", line 248, in execute    prepared = self._cnx.prepare_for_mysql(params)  File "/home/vihanga/lib/python3.8/site-packages/mysql/connector/connection_cext.py", line 626, in prepare_for_mysql    result = self._cmysql.convert_to_mysql(*params)_mysql_connector.MySQLInterfaceError: Python type tuple cannot be converted如果您能向我解釋它是如何工作的并可能幫助我解決錯誤，我將不勝感激。