Selenium 模拟浏览器动态加载页面的实现方法

时间:2022-10-27 22:10:40

相信爬取大公司的数据时,常常会遇到页面信息动态加载的问题,

如果仅仅使用content = urllib2.urlopen(URL).read(),估计信息是获取不全的,这时候就需要模拟浏览器加载页面的过程,

selenium提供了方便的方法,我也是菜鸟,试了很多种方式,下面提供觉得最靠谱的(已经证明对于爬取新浪微博的topic、twitter under topic完全没问题)。

至于下面的browser变量是什么,看前面的几篇文章。

首先是请求对应的URL:

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right_URL = URL.split("from")[0] + "current_page="+str(current_page) + "&since_id="+str(since_id) + "&page="+str(page_index) + "#Pl_Third_App__"+str(Pl_Third_App)
print right_URL
try:
browser.get(right_URL)
print "loading more, sleep 3 seconds ... 0"
time.sleep(3) # NO need for this sleep, but we add ...
browser = selenuim_loading_more(browser, method_index=0)
except:
print "one exception happen ==> get_tweeter_under_topic 2 ..."
pass

然后模拟浏览器,加载更多(推荐使用method_index=0,已经证明比其他好用很多):

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def selenuim_loading_more(browser, method_index=0):
  if method_index==0:
    browser.implicitly_wait(3) # 为了快速滑动,先设置超时时间为1秒
    # while True:
    for i in range(1, 4): # at most 3 times
      print "loading more, window.scrollTo bettom for the", i,"time ..."
      browser.execute_script("window.scrollTo(0,document.body.scrollHeight);")
      try:
        # 定位页面底部的换页tab
        browser.find_element_by_css_selector("div[class='W_pages']")
        break # 如果没抛出异常就说明找到了底部标志,跳出循环
      except NoSuchElementException:
        pass # 抛出异常说明没找到底部标志,继续向下滑动
    browser.implicitly_wait(4) # 将超时时间改回10秒
  elif method_index==1:
    browser.find_element_by_css_selector("div[class='empty_con clearfix']").click() # loading more
    print "loading more, sleep 4 seconds ... 1"
    time.sleep(4)
    browser.find_element_by_css_selector("div[class='empty_con clearfix']").click() # loading more
    print "loading more, sleep 3 seconds ... 2"
    time.sleep(2)
  elif method_index==2:
    load_more_1 = browser.find_element_by_css_selector("div[class='empty_con clearfix']") # loading more        
    ActionChains(browser).click(load_more_1).perform()
    print "loading more, sleep 4 seconds ... 1"
    time.sleep(4)
    load_more_2 = browser.find_element_by_css_selector("div[class='empty_con clearfix']") # loading more        
    ActionChains(browser).click(load_more_2).perform()
    print "loading more, sleep 3 seconds ... 2"
    time.sleep(2)
  elif method_index==3:
    print "loading more, sleep 4 seconds ... 1"
    element = WebDriverWait(browser, 4).until(
      EC.element_to_be_clickable((By.CSS_SELECTOR, "div[class='empty_con clearfix']"))
    )
    element.click()
    print "loading more, sleep 2 seconds ... 2"
    WebDriverWait(browser, 2).until(
      EC.element_to_be_clickable((By.CSS_SELECTOR, "div[class='empty_con clearfix']"))
    ).click()
  return browser

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持服务器之家。

原文链接:https://blog.csdn.net/mmc2015/article/details/53366452