python - 如果找不到元素或 Selenium 等待函数中发生超时异常，如何跳到下一个 url

Question

我正在尝试从天气站点上抓取每日观测表。我有下面的代码来获取特定的表:

#Iterate request to each weather station and date
for station,month,year in product(weather_station,month,year): 
    
    areacode = weather_station[station]['areacode']
    
    #Set link according to data need
    driver.get('https://www.wunderground.com/history/monthly/'+countrycode+'/'+station+'/'+areacode+'/date/'+str(year)+'-'+str(month))
    
    #Wait webpage to fully load necessary tables
    wait = WebDriverWait(driver, 15)
    
    #Update xpath incase webpage html format changes
    xpath_html_loc='//*[@id="inner-content"]/div[2]/div[1]/div[5]/div[1]/div/lib-city-history-observation/div/div[2]/table'
    tables = wait.until(EC.presence_of_all_elements_located((By.XPATH, xpath_html_loc)))
    
    #Save only the necessary table from loaded webpage
    for table in tables:
        histo_table = pd.read_html(table.get_attribute('outerHTML'))
        histo_weather = histo_table[2].fillna('')
        
    print("Weather observations for ",str(month), "-", str(year)," from station",station, "is ready \n")

此代码遍历站点中所有必要的页面，并且在获取我想要的特定表时工作正常，但是当页面中不存在该表或链接不可用时，它返回此错误: timeoutexception
我读到了 try and except 选项，但在这种情况下我似乎无法让它工作。你能建议一个更好的工作解决方案吗？下面带有 try 和 except 的代码仍然输出 timeoutexception 错误。如果表元素不存在或链接不可用，我希望有一个代码跳过当前 url 并转到下一个(即返回到 for 循环的开头以迭代下一个)。

try:
    #Set link according to data need
    driver.get('https://www.wunderground.com/history/monthly/'+countrycode+'/'+station+'/'+areacode+'/date/'+str(year)+'-'+str(month))

    #Wait webpage to fully load necessary tables
    wait = WebDriverWait(driver, 15)

    #Update xpath incase webpage html format changes
    xpath_html_loc='//*[@id="inner-content"]/div[2]/div[1]/div[5]/div[1]/div/lib-city-history-observation/div/div[2]/table'
    tables = driver.find_elements(By.XPATH, xpath_html_loc)
    print(tables)
except TimeoutException as exception:
    raise exception

Answer 1

我能够使用以下解决方法:

for link in links
    try:
        print("Trying for ",link)
        #Set link according to data need
        driver.get(link)
        #Wait webpage to fully load necessary tables
        wait = WebDriverWait(driver, 15)

        #Update xpath incase webpage html format changes
        xpath_html_loc='//*[@id="inner-content"]/div[2]/div[1]/div[5]/div[1]/div/lib-city-history-observation/div/div[2]/table'
        wait.until(EC.presence_of_all_elements_located((By.XPATH, xpath_html_loc)))
        tables = driver.find_elements(By.XPATH, xpath_html_loc)
    except:
        # If the loading took too long, print message
        print("Loading took too long! Data unavailable")
        continue
    
    if(len(tables)>0:
        #Do code here
    else:
       print("data is unavailable")
       continue

即使链接不可用或由于 try 和 except 代码而无法加载表，循环也会继续(这避免了超时异常)。我使用了 wait.until 预期条件(完全加载网页和我需要的表格)和 find_elements (定位特定表格)。如果在页面中找不到表格，或者即使在加载网页后它确实不可用，下面@Dilip 建议的 if-else 代码将继续 for 循环。
感谢你的帮助!