关于python:http分片请求python分片下载文件

源文件

http://theday.guohongfu.top/letter.txt 内容为 abcdefghijklmnopqrstuvwxyz

获取第 20 字节及当前的内容

import requests

url = 'http://theday.guohongfu.top/letter.txt'

headers1 = {'Range': "bytes=20-"  # 获取 第 20 字节及当前的}
response = requests.get(url, headers=headers1)
print('data={}'.format(response.content.decode()))  # abcdef


# 后果
#data=uvwxyz

设置 If-Match 判断文件在两次申请间是否产生了扭转

import requests

url = 'http://theday.guohongfu.top/letter.txt'

headers1 = {'Range': "bytes=0-5"  # 获取 0 -5 的字节}

response = requests.get(url, headers=headers1)
print('data={}'.format(response.content.decode()))  # abcdef
# 失去 etag
req_etag = response.headers['ETag']
headers1['If-Match'] = req_etag # 判断文件在两次申请间是否产生了扭转
headers1['Range'] = 'bytes=6-10'  # 获取 6 -10 字节的数据
response = requests.get(url, headers=headers1)
print('data={}'.format(response.content.decode()))  # ghijk

失去后果：

# data=abcdef
# data=ghijk

应用 Python 分片下载文件

import requests

mp4url = 'https://mp4.vjshi.com/2020-11-20/1c28d06e0278413bf6259ba8b9d26140.mp4'
response = requests.get(mp4url, stream=True)
with open('test.mp4', 'wb') as f:
    [f.write(chunk) for chunk in response.iter_content(chunk_size=512) if chunk]

每次以 512 字节进行下载数据，避免下载文件过大而被一次性读取到内存中，导致内存爆满。