python request文件下载续传

request_c.py

#!/usr/bin/env python

# encoding: utf-8
"""
@author: xl7dev
"""
import sys
import os
import cgi
import re
import datetime
import requests


class DOWNLOAD():
   def getOffset(self, local_path):
      """
      获取已下载文件大小
      :param local_path:
      :return:
      """
      if os.path.exists(local_path):
         return os.path.getsize(local_path)
      else:
         return 0

   def dl(self, url):
      """
      下载文件
      :param url:
      :return:
      """
      # 获取文件属性
      r = requests.head(url)
      start_time = datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")
      filesize = int(r.headers['Content-Length'])  # 获取下载文件大小
      if 'Content-disposition' in r.headers:
         value, params = cgi.parse_header(r.headers['Content-disposition'])
         filename = params['filename']  # 获取下载文件名
      else:
         filename = url.split('/')[-1]
      # 检查断点续传
      start = self.getOffset(filename)
      if start != filesize:
         end = int(filesize) - 1
         range = "bytes={0}-{1}".format(start, end)
         headers = {"Range": range}
         # 开始下载
         r = requests.get(url, stream=True, headers=headers, verify=False)
         with open(filename, 'ab+') as f:
            for chunk in r.iter_content(chunk_size=1024):
               if chunk:
                  print(chunk)
                  f.write(chunk)
         end_time = datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")
         item = {"filename": filename, "filesize": filesize, "start_time": start_time,
               "end_time": end_time, "url":url}
         print(item)
         return item
      else:
         print("Download file {0} completed!".format(filename))


if __name__ == "__main__":
   url = sys.argv[1]
   demo = DOWNLOAD()
   demo.dl(url)