求推荐一个Python的多线程HTTP下载库

对于Python的多线程HTTP下载，我首推 aiohttp 配合 asyncio。虽然它基于异步IO，但通过 asyncio.gather() 可以轻松实现并发下载，效率远超传统多线程。下面是一个完整示例：

import aiohttp
import asyncio
import os

async def download_file(session, url, save_path):
    try:
        async with session.get(url) as response:
            if response.status == 200:
                with open(save_path, 'wb') as f:
                    while True:
                        chunk = await response.content.read(8192)
                        if not chunk:
                            break
                        f.write(chunk)
                print(f"下载完成: {save_path}")
            else:
                print(f"下载失败 {url}: HTTP {response.status}")
    except Exception as e:
        print(f"下载出错 {url}: {e}")

async def download_multiple(urls, save_dir):
    if not os.path.exists(save_dir):
        os.makedirs(save_dir)
    
    async with aiohttp.ClientSession() as session:
        tasks = []
        for i, url in enumerate(urls):
            filename = url.split('/')[-1] or f"file_{i}"
            save_path = os.path.join(save_dir, filename)
            task = download_file(session, url, save_path)
            tasks.append(task)
        
        await asyncio.gather(*tasks)

# 使用示例
if __name__ == "__main__":
    urls = [
        "https://example.com/file1.zip",
        "https://example.com/file2.zip",
        "https://example.com/file3.zip"
    ]
    
    asyncio.run(download_multiple(urls, "./downloads"))

如果你坚持要用传统多线程，可以用 concurrent.futures：

import requests
from concurrent.futures import ThreadPoolExecutor
import os

def download_worker(url, save_path):
    try:
        r = requests.get(url, stream=True)
        with open(save_path, 'wb') as f:
            for chunk in r.iter_content(chunk_size=8192):
                f.write(chunk)
        print(f"下载完成: {save_path}")
    except Exception as e:
        print(f"下载失败 {url}: {e}")

def download_with_threads(urls, save_dir, max_workers=5):
    if not os.path.exists(save_dir):
        os.makedirs(save_dir)
    
    with ThreadPoolExecutor(max_workers=max_workers) as executor:
        futures = []
        for i, url in enumerate(urls):
            filename = url.split('/')[-1] or f"file_{i}"
            save_path = os.path.join(save_dir, filename)
            future = executor.submit(download_worker, url, save_path)
            futures.append(future)
        
        # 等待所有任务完成
        for future in futures:
            future.result()

# 使用示例
urls = ["https://example.com/file1.zip", "https://example.com/file2.zip"]
download_with_threads(urls, "./downloads")

用 aiohttp 吧，现在异步才是王道。