如何使用硒選擇沒有ID的下拉菜單

Question

我嘗試通過CSS選擇器選擇頁面上的下拉菜單（沒有ID），但無法正常工作。 這是下拉代碼：

<select style="margin: 5px auto; width: 146px;" onchange="document.getElementById('11qq').src=this.options[this.selectedIndex].value;">
<option value="https://player.vimeo.com/video/158733095">Shakedown</option>
<option value="x">Placeholder</option>
<option value="https://player.vimeo.com/video/158815551">Race</option>
</select>

我嘗試使用以下代碼選擇每個下拉菜單元素，然后要查找相關的視頻數據（請注意，我假設我不知道下拉菜單的內容，因為我希望它能正常工作對於該網站上的任何下拉菜單）：

from bs4 import BeautifulSoup
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.support.ui import Select
import urllib2

url = "http://racing4everyone.eu/2016/03/12/formula-e-201516-round05-mexico/"
page = urllib2.urlopen(url)
soup = BeautifulSoup(page.read(), "html.parser")

dropdown = [x.text for x in soup.find_all('option')]

driver = webdriver.Firefox()
driver.get("http://racing4everyone.eu/2016/03/12/formula-e-201516-round05-mexico/")

for x in dropdown:
    Select droplist = new Select(driver.findElement(By.CSS_SELECTOR("select")));
    droplist.selectByVisibleText(x);

    frame_video = wait.until(EC.presence_of_element_located((By.CSS_SELECTOR, "iframe[src*=video]")))
    driver.switch_to.frame(frame_video)
    wait.until(EC.presence_of_element_located((By.CSS_SELECTOR, ".controls")))
    page_source = driver.page_source
    driver.close()

    soup = BeautifulSoup(page_source, "html.parser")
    script = soup.find_all("script")
    # A couple of other operations follow to isolate the relevant data from the script data

我從下面的stackoverflow討論中獲得了Select droplist部分（第二個答案）。 但是，出現以下錯誤：

Select droplist = new Select(driver.findElement(By.CSS_SELECTOR("select")));
                  ^
SyntaxError: invalid syntax

Answer 1

也許您在python中使用java methond。 以下是Java方法：

Select droplist = new Select(driver.findElement(By.CSS_SELECTOR("select")));

以下是Python方法：

droplist = driver.find_element_by_css_selector('select')

Answer 2

我將使用項目的值來找到下拉列表。 這是您的頁面的有效示例：

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.support.ui import Select

driver = webdriver.Firefox()
wait = WebDriverWait(driver, 10)

driver.get("http://racing4everyone.eu/2016/03/12/formula-e-201516-round05-mexico/")

for x in ["Shakedown", "Race"]:
  # select the option
  Select(driver.find_element_by_xpath("//select[option='" + x + "']")).select_by_visible_text(x)

  # set context on the video frame
  frame_video = wait.until(EC.presence_of_element_located((By.CSS_SELECTOR, "iframe[src*=video]")))
  driver.switch_to.frame(frame_video)

  # set the default context
  driver.switch_to_default_content()

driver.quit()

請注意，第二項“ PlaceHolder”沒有鏈接。

Answer 3

您嘗試使用onchange屬性

driver.find_element_by_css_selector('onchange*="document.getElementById('11qq')"')

這將為您提供具有onchange屬性的元素witch包含"document.getElementById('11qq')"的元素。