python 念听网mp3多线程多任务下载

#coding=utf-8import requestsimport threadingimport reclass downloader:    # 构造函数    def __init__(self,downloadurl):        # 设置url        #downloadurl='http://file.ting55.com/down/2016/10/8030/15.mp3?s=nb2ZbTb7gOGbMQ4JybtcpQ&e=1490250302&n=五大贼王1落马青云_15.mp3'        self.url = downloadurl.split('&n=')[0]        # 设置线程数        self.num = 8        # 文件名从url最后取        self.name = downloadurl.split('&n=')[1]        # 用head方式去访问资源        r = requests.head(self.url)        # 取出资源的字节数        self.total = int(r.headers['Content-Length'])        print 'total is %s' % (self.total)    def get_range(self):        ranges = []        # 比如total是50,线程数是4个。offset就是12        offset = int(self.total / self.num)        for i in range(self.num):            if i == self.num - 1:                # 最后一个线程，不指定结束位置，取到最后                ranges.append((i * offset, ''))            else:                # 没个线程取得区间                ranges.append((i * offset, (i + 1) * offset))        # range大概是[(0,12),(12,24),(25,36),(36,'')]        return ranges    def download(self, start, end):        headers = {'Range': 'Bytes=%s-%s' % (start, end), 'Accept-Encoding': '*'}        # 获取数据段        res = requests.get(self.url, headers=headers)        # seek到指定位置        print '%s:%s download success' % (start, end)        self.fd.seek(start)        self.fd.write(res.content)    def run(self):        # 打开文件，文件对象存在self里        self.fd = open(r'E:/PycharmProjects/download/output/'+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            # 开线程            thread = threading.Thread(target=self.download, args=(start, end))            thread.start()            thread_list.append(thread)        for i in thread_list:            # 设置等待            i.join()        print 'download %s load success' % (self.name)        self.fd.close()def getPage(url):    html=requests.get(url)    content=html.text    #print content    return contentdef getDownloadUrls(page_content):    pattern=re.compile(r'<a href="(.*?)".*?>',re.S)    downloadUrls=re.findall(pattern,page_content)    return downloadUrls[-11]if __name__ == '__main__':    for i in xrange(1, 61):        url = "http://ting55.com/down/8030-%d" % i        page_content = getPage(url)        downloadLink = getDownloadUrls(page_content)        # 新建实例        down = downloader(downloadLink)        # 执行run方法        down.run()