如何在Python中使用多线程抓取过程读取和写入文件？获取Windows错误32

Question

我想从文本文件中使用参数来刮取链接并将结果写入csv文件。但是当我尝试使用多线程实现它时，出现以下错误::

WindowsError: [Error 32] The process cannot access the file because it is being used by another process:  
'c:\\users\\appdata\\local\\temp\\tmpqseulj.webdriver.xpi\\components\\wdIStatus.xpt' 

请帮助解决问题。 内联是代码

from selenium import webdriver 
from selenium.webdriver.common.by import By 
from selenium.webdriver.common.keys import Keys 
from selenium.webdriver.support.ui import Select 
from selenium.common.exceptions import NoSuchElementException 
import unittest, time, re 
from threading import Thread 
import urlparse 
import urllib2 
import sys; 
import csv 
import operator 
reload(sys); 
sys.setdefaultencoding("utf8") 


with open("C:\\Test2.csv", "w") as f: 
    fieldnames = ("SearchQuery", "Title") 
    output = csv.writer(f, delimiter=",") 
    output.writerow(fieldnames) 


def th(ur):  
    driver = webdriver.Firefox() 
    driver.get("https://www.google.com/search?q="+ur) 
    time.sleep(20); 

    html_source = driver.page_source 

    regex = '<span class="label">(.*?)</span>' 
    pattern = re.compile(regex) 

    Cluster = re.findall(pattern, html_source) 
    Cluster = [H.replace("All Topics","") for H in Cluster] 
    Cluster = [H.replace("Other topics","") for H in Cluster] 
    Cluster = filter(operator.methodcaller('strip'), Cluster) 

    print ur, str(Cluster) 

    output.writerow([ur, HotelName]) 
    driver.close(); 


Symbolfile = open("Result.txt") 
Symbollist = Symbolfile.read() 
new = Symbollist.split("\n") 


threadlist = [] 

for u in new:        # thread implementation 
    t = Thread(target=th, args=(u,)) 
    t.start() 
    threadlist.append(t) 

for b in threadlist: 
    b.join() 

Answer 1

您需要使用锁，如果多个线程将被写入同一个文件。

这看起来像一个合理的例子：http://www.laurentluce.com/posts/python-threads-synchronization-locks-rlocks-semaphores-conditions-events-and-queues/

“打印”也是不是线程安全的。