Python + splinter + http: Error - httplib.ResponseNotReady

Question

使用splinter和Python，我有两个线程正在运行，每个线程访问相同的主URL，但是访问不同的路由，例如线程一次命中：mainurl.com/threadone和线程两次命中：mainurl.com/threadtwo使用：

from splinter import Browser
browser = Browser('chrome')

但是遇到了以下错误：

Traceback (most recent call last):
  File "multi_thread_practice.py", line 299, in <module>
    main()
  File "multi_thread_practice.py", line 290, in main
    first_method(r)
  File "multi_thread_practice.py", line 195, in parser
    second_method(title, name)
  File "multi_thread_practice.py", line 208, in confirm_product
    third_method(current_url)
  File "multi_thread_practice.py", line 214, in buy_product
    browser.visit(url)
  File "/Users/joshua/anaconda/lib/python2.7/site-packages/splinter/driver/webdriver/__init__.py", line 184, in visit
    self.driver.get(url)
  File "/Users/joshua/anaconda/lib/python2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 261, in get
    self.execute(Command.GET, {'url': url})
  File "/Users/joshua/anaconda/lib/python2.7/site-packages/selenium/webdriver/remote/webdriver.py", line 247, in execute
    response = self.command_executor.execute(driver_command, params)
  File "/Users/joshua/anaconda/lib/python2.7/site-packages/selenium/webdriver/remote/remote_connection.py", line 464, in execute
    return self._request(command_info[0], url, body=data)
  File "/Users/joshua/anaconda/lib/python2.7/site-packages/selenium/webdriver/remote/remote_connection.py", line 488, in _request
    resp = self._conn.getresponse()
  File "/Users/joshua/anaconda/lib/python2.7/httplib.py", line 1108, in getresponse
    raise ResponseNotReady()
httplib.ResponseNotReady

什么是错误，我应该如何处理这个问题？

事先谢谢你，一定会投票/接受答复。

代码添加了

import time
from splinter import Browser
import threading

browser = Browser('chrome')

start_time = time.time()

urlOne = 'http://www.practiceurl.com/one'
urlTwo = 'http://www.practiceurl.com/two'
baseUrl = 'http://practiceurl.com'

browser.visit(baseUrl)

def secondThread(url):
    print 'STARTING 2ND REQUEST: ' + str(time.time() - start_time)
    browser.visit(url)
    print 'END 2ND REQUEST: ' + str(time.time() - start_time)


def mainThread(url):
    print 'STARTING 1ST REQUEST: ' + str(time.time() - start_time)
    browser.visit(url)
    print 'END 1ST REQUEST: ' + str(time.time() - start_time)


def main():
    threadObj = threading.Thread(target=secondThread, args=[urlTwo])
    threadObj.daemon = True

    threadObj.start()

    mainThread(urlOne)

main()

Answer 1

据我所知，在一个浏览器上，您要做的事情是不可能的。Splinter是在实际的浏览器上运行的，因此，同时传入许多命令会导致问题。它的作用就像人类会与浏览器交互一样(当然是自动化的)。可以打开许多浏览器窗口，但如果没有收到来自上一个请求的响应，则无法在不同的线程中发送请求。这会导致CannotSendRequest错误。因此，我建议您(如果需要使用线程)打开两个浏览器，然后使用线程通过每个浏览器发送请求。否则，这是不可能的。

这个线程在selenium上，但是信息是可传输的。Selenium多选项卡一次，这说明了你想要做的事情(我想)是不可能的。绿色勾选回答者也给出了我同样的建议。

希望这不会让你偏离轨道，并帮助你走出困境。

编辑:只是为了显示：

import time
from splinter import Browser
import threading

browser = Browser('firefox')
browser2 = Browser('firefox')

start_time = time.time()

urlOne = 'http://www.practiceurl.com/one'
urlTwo = 'http://www.practiceurl.com/two'
baseUrl = 'http://practiceurl.com'

browser.visit(baseUrl)


def secondThread(url):
    print 'STARTING 2ND REQUEST: ' + str(time.time() - start_time)
    browser2.visit(url)
    print 'END 2ND REQUEST: ' + str(time.time() - start_time)


def mainThread(url):
    print 'STARTING 1ST REQUEST: ' + str(time.time() - start_time)
    browser.visit(url)
    print 'END 1ST REQUEST: ' + str(time.time() - start_time)


def main():
    threadObj = threading.Thread(target=secondThread, args=[urlTwo])
    threadObj.daemon = True

    threadObj.start()

    mainThread(urlOne)

main()

请注意，我使用firefox是因为我没有安装chromedriver。

在浏览器打开后设置一个等待，以确保浏览器在计时器开始之前已经完全就绪，这可能是个好主意。

Answer 2

@GenericSnake在这个问题上是正确的。为了增加一点，我强烈建议您重构代码以使用多处理库，主要是因为线程实现使用了吉尔。

在CPython中，由于全局解释器锁，只有一个线程可以一次执行Python代码(尽管某些面向性能的库可能克服了这个限制)。如果您希望您的应用程序更好地利用多核计算机的计算资源，建议您使用多处理。但是，如果要同时运行多个I/O绑定任务，线程仍然是一个合适的模型。

实际上，使用多重处理的一个好处是，您可以重构代码以避免重复的方法secondThread和mainThread，例如这种方法(最后一件事，不要忘记清理您使用的资源，比如一旦完成就关闭浏览器的browser.quit() )：

import time
from splinter import Browser
from multiprocessing import Process
import os

os.environ['PATH'] = os.environ[
                         'PATH'] + "path/to/geckodriver" + "path/to/firefox/binary"

start_time = time.time()

urlOne = 'http://pythoncarsecurity.com/Support/FAQ.aspx'
urlTwo = 'http://pythoncarsecurity.com/Products/'



def url_visitor(url):
    print("url called: " + url)
    browser = Browser('firefox')
    print('STARTING  REQUEST TO: ' + url + " at "+ str(time.time() - start_time))
    browser.visit(url)
    print('END REQUEST TO: ' + url + " at "+ str(time.time() - start_time))   

def main():
    p1 = Process(target=url_visitor, args=[urlTwo])
    p2 = Process(target=url_visitor, args=[urlOne])
    p1.start()
    p2.start()
    p1.join() #join processes to the main process to see the output
    p2.join()

if __name__=="__main__":
    main()

这将给出以下输出(但时间将取决于您的系统)：

url called: http://pythoncarsecurity.com/Support/FAQ.aspx
url called: http://pythoncarsecurity.com/Products/
STARTING  REQUEST TO: http://pythoncarsecurity.com/Support/FAQ.aspx at 10.763000011444092
STARTING  REQUEST TO: http://pythoncarsecurity.com/Products/ at 11.764999866485596
END REQUEST TO: http://pythoncarsecurity.com/Support/FAQ.aspx at 16.20199990272522
END REQUEST TO: http://pythoncarsecurity.com/Products/ at 16.625999927520752

编辑：多线程和Selenium的问题是浏览器实例不是线程安全的，我发现避免这个问题的唯一方法是获取url_visitor上的一个锁，但是在这种情况下，您就失去了多线程的优势。这就是为什么我认为使用多个浏览器更有益处(尽管我猜您有一些非常具体的要求)，请参见下面的代码：

import time
from splinter import Browser
import threading
from threading import Lock
import os

os.environ['PATH'] = os.environ[
                         'PATH'] + "/path/to/chromedriver"

start_time = time.time()

urlOne = 'http://pythoncarsecurity.com/Support/FAQ.aspx'
urlTwo = 'http://pythoncarsecurity.com/Products/'
browser = Browser('chrome')
lock = threading.Lock()#create a lock for the url_visitor method

def init():
    browser.visit("https://www.google.fr")
    driver = browser.driver
    driver.execute_script("window.open('{0}', '_blank');") #create a new tab
    tabs = driver.window_handles


def url_visitor(url, tabs):
    with lock:
        if tabs != 0:
            browser.driver.switch_to_window(browser.driver.window_handles[tabs])
        print("url called: " + url)
        print('STARTING  REQUEST TO: ' + url + " at "+ str(time.time() - start_time))
        browser.visit(url)
        print('END REQUEST TO: ' + url + " at "+ str(time.time() - start_time))
        browser.quit()


def main():
    p1 = threading.Thread(target=url_visitor, args=[urlTwo, 0])
    p2 = threading.Thread(target=url_visitor, args=[urlOne, 1])
    p1.start()
    p2.start()

if __name__=="__main__":
    init() #create a browser with two tabs
    main()