def josaa_scrape():
    """
    Sample usage: df = josaa_scrape("2018", "1")
    df.info()
    """
    with requests.Session() as s:
        R = s.get(url, headers=headers)
        data = {}

        for key, value in params.items():
            data.update({tag['name']: tag['value'] for tag in BeautifulSoup(R.content, 'lxml').select('input[name^=__]')})
            data[key] = value
            R = s.post(url, data=data)

    table = BeautifulSoup(R.text, 'lxml').find(id = 'GridView1')
    df = pd.read_html(table.prettify())[0]
    df.dropna(inplace = True, how="all")

    return df

它抛出了一个错误“NoneType”对象没有属性“pretify”。我已经检查了所有ID。