python - 脚本突然停止爬行，没有错误或异常

问题描述

我不知道为什么，但是我的脚本在到达第 9 页后总是停止爬行。没有错误、异常或警告，所以我有点不知所措。

有人可以帮帮我吗？

def initiate_crawl():
    def refresh_page(url):
        ff = create_webdriver_instance()
        ff.get(url)
        ff.find_element(By.XPATH, '//*[@id="FilterItemView_sortOrder_dropdown"]/div/span[2]/span/span/span/span').click()
        ff.find_element(By.XPATH, '//a[contains(text(), "Discount - High to Low")]').click()
        items = WebDriverWait(ff, 15).until(
            EC.visibility_of_all_elements_located((By.XPATH, '//div[contains(@id, "100_dealView_")]'))
        )
        print(len(items))
        for count, item in enumerate(items):
            slashed_price = item.find_elements(By.XPATH, './/span[contains(@class, "a-text-strike")]')
            active_deals = item.find_elements(By.XPATH, './/*[contains(text(), "Add to Cart")]')
            if len(slashed_price) > 0 and len(active_deals) > 0:
                product_title = item.find_element(By.ID, 'dealTitle').text
                if product_title not in already_scraped_product_titles:
                    already_scraped_product_titles.append(product_title)
                    url = ff.current_url
                    ff.quit()
                    refresh_page(url)
                    break
            if count+1 is len(items):
                try:
                    next_button = WebDriverWait(ff, 15).until(
                        EC.text_to_be_present_in_element((By.PARTIAL_LINK_TEXT, 'Next→'), 'Next→')
                    )
                    ff.find_element(By.PARTIAL_LINK_TEXT, 'Next→').click()
                    url = ff.current_url
                    ff.quit()
                    refresh_page(url)
                except Exception as error:
                    print(error)
                    ff.quit()

    refresh_page('https://www.amazon.ca/gp/goldbox/ref=gbps_ftr_s-3_4bc8_dct_10-?gb_f_c2xvdC0z=sortOrder:BY_SCORE,discountRanges:10-25%252C25-50%252C50-70%252C70-&pf_rd_p=f5836aee-0969-4c39-9720-4f0cacf64bc8&pf_rd_s=slot-3&pf_rd_t=701&pf_rd_i=gb_main&pf_rd_m=A3DWYIK6Y9EEQB&pf_rd_r=CQ7KBNXT36G95190QJB1&ie=UTF8')

initiate_crawl()

打印长度items也会调用一些奇怪的行为。它不是总是返回 32，这将对应于每页上的项目数，而是打印32第一页，64第二页，96第三页，依此类推。我通过使用//div[contains(@id, "100_dealView_")]/div[contains(@class, "dealContainer")]而不是//div[contains(@id, "100_dealView_")]作为items变量的 XPath 来解决这个问题。我希望这就是它在第 9 页遇到问题的原因。我现在正在运行测试。更新：它现在正在抓取第 10 页及以后，因此问题已解决。

标签： pythonseleniumpython-requestsgeckodriverurllib3

解决方案

根据您对该问题的第10^次修订，错误消息...

HTTPConnectionPool(host='127.0.0.1', port=58992): Max retries exceeded with url: /session/e8beed9b-4faa-4e91-a659-56761cb604d7/element (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x0000022D31378A58>: Failed to establish a new connection: [WinError 10061] No connection could be made because the target machine actively refused it'))

...暗示该get()方法未能引发HTTPConnectionPool错误并显示Max retries exceeded消息。

有几件事：

根据讨论max-retries-exceeded 异常令人困惑，回溯有点误导。Requests 包装了异常以方便用户使用。原始异常是显示的消息的一部分。
请求从不重试（它设置了retries=0urllib3's ），因此如果没有MaxRetryError和HTTPConnectionPool关键字HTTPConnectionPool，错误会更加规范。所以一个理想的Traceback应该是：
```
  NewConnectionError(<class 'socket.error'>: [Errno 10061] No connection could be made because the target machine actively refused it)
```
您将在MaxRetryError: HTTPConnectionPool: Max retries exceeded (Caused by ProtocolError('Connection aborted.', error(111, 'Connection denied'))中找到详细说明

解决方案

根据Selenium 3.14.1的发行说明：

* Fix ability to set timeout for urllib3 (#6286)

Merge是：修复urllib3无法设置超时！

结论

升级到Selenium 3.14.1后，您将能够设置超时并查看规范的Tracebacks，并能够采取必要的措施。

参考

一些相关的参考资料：

这个用例

我从codepen.io - A PEN BY Anthony中获取了您的完整脚本。我不得不对您现有的代码进行一些调整，如下所示：

正如你所使用的：

  ua_string = random.choice(ua_strings)

您必须强制导入random为：

    import random

您已创建变量next_button但尚未使用它。我总结了以下四行：

  next_button = WebDriverWait(ff, 15).until(
                  EC.text_to_be_present_in_element((By.PARTIAL_LINK_TEXT, 'Next→'), 'Next→')
              )
  ff.find_element(By.PARTIAL_LINK_TEXT, 'Next→').click()

作为：

  WebDriverWait(ff, 15).until(EC.text_to_be_present_in_element((By.PARTIAL_LINK_TEXT, 'Next→'), 'Next→'))
  ff.find_element(By.PARTIAL_LINK_TEXT, 'Next→').click()

您修改后的代码块将是：

  # -*- coding: utf-8 -*-
  from selenium import webdriver
  from selenium.webdriver.firefox.options import Options
  from selenium.webdriver.common.by import By
  from selenium.webdriver.support import expected_conditions as EC
  from selenium.webdriver.support.ui import WebDriverWait
  import time
  import random


  """ Set Global Variables
  """
  ua_strings = ['Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36']
  already_scraped_product_titles = []



  """ Create Instances of WebDriver
  """
  def create_webdriver_instance():
      ua_string = random.choice(ua_strings)
      profile = webdriver.FirefoxProfile()
      profile.set_preference('general.useragent.override', ua_string)
      options = Options()
      options.add_argument('--headless')
      return webdriver.Firefox(profile)



  """ Construct List of UA Strings
  """
  def fetch_ua_strings():
      ff = create_webdriver_instance()
      ff.get('https://techblog.willshouse.com/2012/01/03/most-common-user-agents/')
      ua_strings_ff_eles = ff.find_elements_by_xpath('//td[@class="useragent"]')
      for ua_string in ua_strings_ff_eles:
          if 'mobile' not in ua_string.text and 'Trident' not in ua_string.text:
              ua_strings.append(ua_string.text)
      ff.quit()



  """ Log in to Amazon to Use SiteStripe in order to Generate Affiliate Links
  """
  def log_in(ff):
      ff.find_element(By.XPATH, '//a[@id="nav-link-yourAccount"] | //a[@id="nav-link-accountList"]').click()
      ff.find_element(By.ID, 'ap_email').send_keys('anthony_falez@hotmail.com')
      ff.find_element(By.ID, 'continue').click()
      ff.find_element(By.ID, 'ap_password').send_keys('lo0kyLoOkYig0t4h')
      ff.find_element(By.NAME, 'rememberMe').click()
      ff.find_element(By.ID, 'signInSubmit').click()



  """ Build Lists of Product Page URLs
  """
  def initiate_crawl():
      def refresh_page(url):
      ff = create_webdriver_instance()
      ff.get(url)
      ff.find_element(By.XPATH, '//*[@id="FilterItemView_sortOrder_dropdown"]/div/span[2]/span/span/span/span').click()
      ff.find_element(By.XPATH, '//a[contains(text(), "Discount - High to Low")]').click()
      items = WebDriverWait(ff, 15).until(
          EC.visibility_of_all_elements_located((By.XPATH, '//div[contains(@id, "100_dealView_")]'))
      )
      for count, item in enumerate(items):
          slashed_price = item.find_elements(By.XPATH, './/span[contains(@class, "a-text-strike")]')
          active_deals = item.find_elements(By.XPATH, './/*[contains(text(), "Add to Cart")]')
          # For Groups of Items on Sale
          # active_deals = //*[contains(text(), "Add to Cart") or contains(text(), "View Deal")]
          if len(slashed_price) > 0 and len(active_deals) > 0:
              product_title = item.find_element(By.ID, 'dealTitle').text
              if product_title not in already_scraped_product_titles:
                  already_scraped_product_titles.append(product_title)
                  url = ff.current_url
                  # Scrape Details of Each Deal
                  #extract(ff, item.find_element(By.ID, 'dealImage').get_attribute('href'))
                  print(product_title[:10])
                  ff.quit()
                  refresh_page(url)
                  break
          if count+1 is len(items):
              try:
                  print('')
                  print('new page')
                  WebDriverWait(ff, 15).until(EC.text_to_be_present_in_element((By.PARTIAL_LINK_TEXT, 'Next→'), 'Next→'))
                  ff.find_element(By.PARTIAL_LINK_TEXT, 'Next→').click()
                  time.sleep(10)
                  url = ff.current_url
                  print(url)
                  print('')
                  ff.quit()
                  refresh_page(url)
              except Exception as error:
                  """
                  ff.find_element(By.XPATH, '//*[@id="pagination-both-004143081429407891"]/ul/li[9]/a').click()
                  url = ff.current_url
                  ff.quit()
                  refresh_page(url)
                  """
                  print('cannot find ff.find_element(By.PARTIAL_LINK_TEXT, "Next?")')
                  print('Because of... {}'.format(error))
                  ff.quit()

      refresh_page('https://www.amazon.ca/gp/goldbox/ref=gbps_ftr_s-3_4bc8_dct_10-?gb_f_c2xvdC0z=sortOrder:BY_SCORE,discountRanges:10-25%252C25-50%252C50-70%252C70-&pf_rd_p=f5836aee-0969-4c39-9720-4f0cacf64bc8&pf_rd_s=slot-3&pf_rd_t=701&pf_rd_i=gb_main&pf_rd_m=A3DWYIK6Y9EEQB&pf_rd_r=CQ7KBNXT36G95190QJB1&ie=UTF8')

  #def extract_info(ff, url):
  fetch_ua_strings()
  initiate_crawl()

控制台输出：使用Selenium v3.14.0和Firefox Quantum v62.0.3，我可以在控制台上提取以下输出：

  J.Rosée Si
  B.Catcher 
  Bluetooth4
  FRAM G4164
  Major Crim
  20% off Oh
  True Blood
  Prime-Line
  Marathon 3
  True Blood
  B.Catcher 
  4 Film Fav
  True Blood
  Texture Pa
  Westinghou
  True Blood
  ThermoPro 
  ...
  ...
  ...

注意：我可以优化您的代码并执行相同的网络抓取操作，只初始化一次Firefox 浏览器客户端并遍历各种产品及其详细信息。但是为了保持你的逻辑和创新，我建议你做一些最小的改变来让你通过。

python - 脚本突然停止爬行，没有错误或异常

问题描述

解决方案

解决方案

结论

参考

这个用例

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