linux高性能服务器编程 下载

import requests

def download_file(url, local_filename):
    with requests.get(url, stream=True) as r:
        r.raise_for_status()
        with open(local_filename, 'wb') as f:
            for chunk in r.iter_content(chunk_size=8192):
                f.write(chunk)

def resume_download(url, local_filename):
    try:
        # Check the size of the local file
        file_size = os.path.getsize(local_filename)
    except FileNotFoundError:
        file_size = 0

    headers = {'Range': f'bytes={file_size}-'}
    with requests.get(url, headers=headers, stream=True) as r:
        r.raise_for_status()
        with open(local_filename, 'ab') as f:
            for chunk in r.iter_content(chunk_size=8192):
                f.write(chunk)

# Usage
url = 'http://example.com/file.zip'
local_filename = 'file.zip'

try:
    download_file(url, local_filename)
except requests.exceptions.RequestException:
    resume_download(url, local_filename)