异步编程实战：构建高性能 Python 网络应用

1 异步编程：为什么它是现代网络应用的必然选择

1.1 同步架构的瓶颈与异步架构的优势

传统同步网络架构就像单车道收费站，每个请求必须等待前车完全通过后才能进入。而异步架构则是多车道智能收费站，车辆在等待时，其他车辆可以继续通行。

import time
import asyncio
import aiohttp
from flask import Flask
import requests

def sync_http_requests():
    urls = ['https://httpbin.org/delay/1'] * 5
    start = time.time()
    for url in urls:
        response = requests.get(url)
        print(f"同步请求完成：{response.status_code}")
    sync_time = time.time() - start
    print(f"同步总耗时：{sync_time:.2f}秒")
    return sync_time

async def async_http_requests():
    urls = ['https://httpbin.org/delay/1'] * 5
    start = time.time()
    async with aiohttp.ClientSession() as session:
        tasks = [session.get(url) for url in urls]
        responses = await asyncio.gather(*tasks)
        for i, response in enumerate(responses):
            print(f"异步请求 {i} 完成：{response.status}")
            await response.release()
    async_time = time.time() - start
    print(f"异步总耗时：{async_time:.2f}秒")
    return async_time

  ():
    sync_time = sync_http_requests()
    async_time =  async_http_requests()
    ()
    ()
    ()
    ()

 __name__ == :
    asyncio.run(performance_comparison())