Python多线程抓取图片效率对比

import requests
import urlparse
import os
import time
import threading
import Queue

path = '/home/lidongwei/scrapy/owan_img_urls.txt'
#path = '/home/lidongwei/scrapy/cc.txt'
fetch_img_save_path = '/home/lidongwei/scrapy/owan_imgs/'

# 读取保存再文件里面400个urls
with open(path) as f :
 urls = f.readlines()

urls = urls[:400]
# 使用Queue来线程通信，因为队列是线程安全的（就是默认这个队列已经有锁）
q = Queue.Queue()
for url in urls:
 q.put(url)

start = time.time()

def fetch_img_func(q):
 while True:
 try:
 # 不阻塞的读取队列数据
 url = q.get_nowait()
 i = q.qsize()
 except Exception, e:
 print e
 break;
 print 'Current Thread Name Runing %s ... 11' % threading.currentThread().name
 url = url.strip()
 img_path = urlparse.urlparse(url).path
 ext = os.path.splitext(img_path)[1]
 print 'handle %s pic... pic url %s ' % (i, url)
 res = requests.get(url, stream=True)

 if res.status_code == 200:
 save_img_path = '%s%s%s' % (fetch_img_save_path, i, ext)
 # 保存下载的图片
 with open(save_img_path, 'wb') as fs:
 for chunk in res.iter_content(1024):
 fs.write(chunk)
 print 'save %s pic ' % i

# 可以开多个线程测试不同效果
t1 = threading.Thread(target=fetch_img_func, args=(q, ), name="child_thread_1")
#t2 = threading.Thread(target=fetch_img_func, args=(q, ), name="child_thread_2")
#t3 = threading.Thread(target=fetch_img_func, args=(q, ), name="child_thread_3")
#t4 = threading.Thread(target=fetch_img_func, args=(q, ), name="child_thread_4")
t1.start()
#t2.start()
#t3.start()
#t4.start()
t1.join()
#t2.join()
#t3.join()
#t4.join()

end = time.time()
print 'Done %s ' % (end-start)

4线程 Done 12.443133831
3线程 Done 12.9201757908 
2线程 Done 32.8628299236
1线程 Done 54.6115460396