python - 使用selenium和phantomjs爬虫遇到的缓存问题 ？

Question

使用selenium和phantomjs爬虫遇到问题，代码如下【【采集时我用了蓝灯软件来代理，不能直接采集】】：

代码如下：

from selenium import webdriver
import time 
driver = webdriver.PhantomJS()
driver.get('http://chuansong.me')
alla = driver.find_elements_by_class_name('question_link')
for a in alla:
    a = a.get_attribute('href')
    print(a)
    driver.get(a)
    title = driver.find_element_by_id('activity-name').text
    writer = driver.find_element_by_id('post-user').text
    content = driver.find_element_by_id('js_content').text
    print(writer,title,content)
    #time.sleep(8)
driver.close()
driver.quit()

能采集到一个网址链接的内容，然后提示错误：

Traceback (most recent call last):
  File "D:/python-work/test.py", line 10, in <module>
    a = a.get_attribute('href')
  File "D:\Program Files\Python35-32\lib\site-packages\selenium\webdriver\remote\webelement.py", line 141, in get_attribute
    resp = self._execute(Command.GET_ELEMENT_ATTRIBUTE, {'name': name})
  File "D:\Program Files\Python35-32\lib\site-packages\selenium\webdriver\remote\webelement.py", line 494, in _execute
    return self._parent.execute(command, params)
  File "D:\Program Files\Python35-32\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 236, in execute
    self.error_handler.check_response(response)
  File "D:\Program Files\Python35-32\lib\site-packages\selenium\webdriver\remote\errorhandler.py", line 192, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.StaleElementReferenceException: Message: {"errorMessage":"Element does not exist in cache","request":{"headers":{"Accept":"application/json","Accept-Encoding":"identity","Connection":"close","Content-Type":"application/json;charset=UTF-8","Host":"127.0.0.1:60284","User-Agent":"Python-urllib/3.5"},"httpVersion":"1.1","method":"GET","url":"/attribute/href","urlParsed":{"anchor":"","query":"","file":"href","directory":"/attribute/","path":"/attribute/href","relative":"/attribute/href","port":"","host":"","password":"","user":"","userInfo":"","authority":"","protocol":"","source":"/attribute/href","queryKey":{},"chunks":["attribute","href"]},"urlOriginal":"/session/bcbced70-c66a-11e6-a824-4b87531d9c78/element/:wdc:1482207278197/attribute/href"}}
Screenshot: available via screen

Answer 1

大神們，我修改了程式碼，但是執行速度非常慢，也禁止了圖片的加載，有時候又出現同樣的問題，請大神給看看，有哪些還可以修改和優化的，代碼如下：

__author__ = 'Administrator'

from selenium import webdriver
import time

cap = webdriver.DesiredCapabilities.PHANTOMJS
cap["phantomjs.page.settings.resourceTimeout"] = 1000
cap["phantomjs.page.settings.loadImages"] = False
#cap["phantomjs.page.settings.javascriptEnabled"] = False
cap["phantomjs.page.settings.localToRemoteUrlAccessEnabled"] = False
driver = webdriver.PhantomJS(desired_capabilities=cap)

#driver = webdriver.PhantomJS()
driver.get('http://chuansong.me')
length = len(driver.find_elements_by_class_name('question_link'))
for i in range(0,length):
    alla = driver.find_elements_by_class_name('question_link')
    a = alla[i]
    print(a)
    if 'question_link' in a.get_attribute('class') or 'n' in a.get_attribute('href'):
        a.click()
        driver.get(a.get_attribute('href'))
        title = driver.find_element_by_id('activity-name').text
        writer = driver.find_element_by_id('post-user').text
        content = driver.find_element_by_id('js_content').get_attribute('outerHTML')
        print(writer,title,content)
        driver.back()
        time.sleep(8)
driver.close()
driver.quit()