python多线程下载器 - vinchoi

python多线程下载器

import requests
import threading

class downloader:
    def __init__(self):
        self.url=\'http://51reboot.com/src/blogimg/pc.jpg\'
        self.num=8
        self.name=self.url.split(\'/\')[-1]
        r = requests.head(self.url)
        self.total = int(r.headers[\'Content-Length\'])
        print \'total is %s\' % (self.total)
    def get_range(self):
        ranges=[]
        offset = int(self.total/self.num)
        for i in  range(self.num):
            if i==self.num-1:
                ranges.append((i*offset,\'\'))
            else:
                ranges.append((i*offset,(i+1)*offset))
        return ranges
    def download(self,start,end):
        headers={\'Range\':\'Bytes=%s-%s\' % (start,end),\'Accept-Encoding\':\'*\'}
        res = requests.get(self.url,headers=headers)
        self.fd.seek(start)
        self.fd.write(res.content)
    def run(self):
        self.fd =  open(self.name,\'w\')
        thread_list = []
        n = 0
        for ran in self.get_range():
            start,end = ran
            print \'thread %d start:%s,end:%s\'%(n,start,end)
            n+=1
            thread = threading.Thread(target=self.download,args=(start,end))
            thread.start()
            thread_list.append(thread)
        for i in thread_list:
            i.join()
        print \'download %s load success\'%(self.name)
        self.fd.close()
if __name__==\'__main__\':
    down = downloader()
    down.run()