Python: Saving a file from the URL by chunks

https://github.com/images/modules/header/logov3-hover.png

f = urllib.urlopen(request.POST['url'])
    p = os.path.join(settings.UPLOAD_DIRECTORY, "saved_file.jpg")
    filesize = 0
    with open(p,'wb') as output:
        while True:
            buf = f.read(65536)
            filesize += len(buf)
            if not buf:
                break
            output.write(buf)