import multiprocessing
import time
# 計算平方的任務(wù)函數(shù)
def calculate_square(number):
    total = 0
    for n in range(number):
        total += n ** 2
    print(f"計算結(jié)果：{total}")
if __name__ == "__main__":  # 必須加這句，否則Windows系統(tǒng)會報錯
    # 創(chuàng)建4個進程
    processes = []
    numbers = [10_000_000, 10_000_000, 10_000_000, 10_000_000]  # 四個大數(shù)
    # 記錄開始時間
    start_time = time.time()
    # 創(chuàng)建并啟動進程
    for num in numbers:
        p = multiprocessing.Process(target=calculate_square, args=(num,))
        processes.append(p)
        p.start()  # 啟動進程（會立即返回，不會等待完成）
    # 等待所有進程完成
    for p in processes:
        p.join()  # 阻塞主進程，直到子進程結(jié)束
    # 計算總耗時
    print(f"總耗時：{time.time() - start_time:.2f}秒")

import threading
import time
import requests
# 全局變量（線程共享）
download_complete = False
def download_file(url):
    global download_complete
    print("開始下載文件...")
    response = requests.get(url)
    with open("bigfile.iso", "wb") as f:
        f.write(response.content)
    download_complete = True
    print("\n下載完成！")
def show_progress():
    while not download_complete:
        print(".", end="", flush=True)  # 不換行輸出點
        time.sleep(0.5)
if __name__ == "__main__":
    # 創(chuàng)建兩個線程
    download_thread = threading.Thread(
        target=download_file, 
        args=("https://example.com/large-file.iso",)
    )
    progress_thread = threading.Thread(target=show_progress)
    # 啟動線程
    download_thread.start()
    progress_thread.start()
    # 等待下載線程完成
    download_thread.join()
    progress_thread.join()  # 需要手動停止進度條線程

import asyncio
import aiohttp  # 需要安裝：pip install aiohttp
async def fetch_page(url):
    async with aiohttp.ClientSession() as session:  # 創(chuàng)建會話
        async with session.get(url) as response:    # 發(fā)起請求
            return await response.text()           # 異步等待響應
async def main():
    urls = [
        "https://www.baidu.com",
        "https://www.taobao.com",
        "https://www.jd.com"
    ]
    # 創(chuàng)建任務(wù)列表
    tasks = [fetch_page(url) for url in urls]
    # 并行執(zhí)行所有任務(wù)
    pages = await asyncio.gather(*tasks)  # 關(guān)鍵點：聚集任務(wù)
    # 輸出結(jié)果
    for url, content in zip(urls, pages):
        print(f"{url} → 長度：{len(content)}")
# 啟動事件循環(huán)
asyncio.run(main())  # Python 3.7+