selenium 把网页的数据加载

把网页课程ID转换一行带"，"隔开的数据
上代码

for a in range(30):
    # 点击查询
    driver.find_element_by_xpath('//*[@id="UserInfo"]/thead/tr[2]/td[6]/div/button[1]').click()
    time.sleep(3)
    # 定义数组
    umn = []
    for j in range(3):
        for i in range(1, 21):
            try:
                t = driver.find_element_by_xpath('//*[@id="UserInfo"]/tbody/tr[{}]/td[1]'.format(i)).text
            except Exception:
                break
            time.sleep(0.2)
            umn.append(t)
            umn.append(",")

        # 点击第2页
        try:
            driver.find_element_by_xpath('//*[@id="UserInfo_wrapper"]/div[3]/div[1]/div[1]/div/a[2]/i').click()
            time.sleep(2)
        except Exception:
            break

    print(umn)
    time.sleep(2)
    # 切换到声网页
    driver.get("http://aclassroomadmin-uat.acadsoc.com.cn/TeacherInfo/AgoraNetlessCourseLessonIndex")
    time.sleep(1)
    # 点击批量创建
    driver.find_element_by_xpath('//*[@id="BatchAdd"]').click()
    time.sleep(0.5)
    # 把课程ID填入
    driver.find_element_by_xpath('//*[@id="input_clids"]').send_keys(umn)
    time.sleep(2)
    # 点击创建
    driver.find_element_by_xpath('//*[@id="submit"]').click()
    while True:
        try:
            alert = driver.switch_to.alert  # 进入警告框，得到警告框对象
            alert.accept()  # 点击确认
            print("今天课程已全部转声网，感谢你的使用！！")
            # 清空课程ID
            umn.clear()

        except Exception:
            print('课程正在转换中')
            time.sleep(2)
        else:
            break