python 之实现断点下载与下载进度条

一、效果图

二、进度条代码

__author__ = 'Yang'
 
import os
import time
from threading import Thread
 
'''下载进度条'''
class Down_progress(object):
 
    def __init__(self, total, init_size, dst):
        # 文件总大小
        self.total = total
        # 下载大小
        self.init_size = init_size
        # 文件保存路径
        self.dst = dst
 
    def start(self):
        def start():
            start_time = time.time()
            print('[文件大小]：%.2f MB' % ((self.total - self.init_size) / 1024 / 1024))
 
            while self.init_size < self.total:
                speed_str = ''
                if os.path.exists(self.dst):
                    # 计算下载率
                    start = self.init_size
                    time.sleep(1)
                    down_speed = (self.init_size - start) / 1024
                    if down_speed > 1024:
                        speed_str = '%.2f MB/s' % (down_speed / 1024)
                    else:
                        speed_str = '%.2f kb/s' % down_speed
                    print('\r' + '[下载进度]：[%s]%.2f%%，下载速度：%s' % ('#' * int(self.init_size * 50 / self.total), float(self.init_size / self.total * 100), speed_str), end = '')
 
            # 计算下载时间
            offset_time = time.time() - start_time
            if offset_time > 60:
                offset_time = '%.2f 分钟' % (offset_time / 60)
            else:
                offset_time = '%.2f 秒' % offset_time
            print('\n' + '下载完成，耗时：%s' % offset_time)
 
        th = Thread(target = start)
        th.start()
 
    ''' 更新下载大小'''
    def update(self, size):
        self.init_size += size

三、断点下载例子

import requests, re, os
from threading import Thread
from down_progress import *
 
host = "http://www.8080s.net"
url = "http://www.8080s.net/movie/32088"
headers = {'User-Agent': 'Mozilla/5.0 (iPhone; CPU iPhone OS 9_1 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Version/9.0 Mobile/13B143 Safari/601.1'}
 
''' 断点下载'''
def down(url, dst):
    try:
        response = requests.get(url, stream=True, verify=False)
        file_size = int(response.headers['content-length'])
        if os.path.exists(dst):
            first_size = os.path.getsize(dst)
        else:
            first_size = 0
        if file_size <= first_size:
            return
        headers['Range'] = "bytes=%d-" % (first_size, )
        print("开始下载："+url)
        res = requests.get(url, stream=True, headers=headers, verify=False)
        with open(dst, "ab") as f:
            dp = Down_progress(file_size, first_size, dst)
            dp.start()
            chunk_size = 1024
            for chunk in res.iter_content(chunk_size = chunk_size):
                if chunk:
                    f.write(chunk)
                    dp.update(chunk_size)
    except Exception as e:
        print(e)
 
if __name__ == '__main__':
    res = requests.get(url)
    content = res.text
    a = re.findall(r"<a[^>]*\s+href=[\'\"]?([^\'\"]*)[\'\"]?[^>]*\s+>.*<\/", content)
    down(a[0], './%s' % os.path.basename(a[0]))