import threading
import time

def heartbeat():
    for i in range(2):
        print(f"心跳 {i} [{time.strftime('%H:%M:%S')}]")
        time.sleep(5)

# 注意：没有设 daemon=True，所以是普通线程
t = threading.Thread(target=heartbeat)
t.start()
time.sleep(2)
print(f"主程序要退出了... [{time.strftime('%H:%M:%S')}]")
# 线程刚发完心跳 0，正卡在 sleep(5) 的第 2 秒
# Python 会等非 daemon 线程结束才退出，还得等约 8 秒

import threading
import logging
import time

logging.basicConfig(level=logging.DEBUG, format="%(threadName)s: %(message)s")

def worker(interval, stop_event):
    while not stop_event.is_set():
        logging.debug("工作中...")
        stop_event.wait(timeout=interval)
    logging.debug("退出")

stop_event = threading.Event()
t1 = threading.Thread(target=worker, args=(2, stop_event), name="Worker-1")
t2 = threading.Thread(target=worker, args=(3, stop_event), name="Worker-2")
t1.start()
t2.start()

try:
    while not stop_event.wait(timeout=5):
        logging.debug("主线程仍在运行")
except KeyboardInterrupt:
    logging.debug("收到中断信号")
    stop_event.set()

t1.join()
t2.join()
logging.debug("所有线程已退出")

import asyncio
import time

async def task(name, delay):
    print(f"{time.strftime('%H:%M:%S')} {name} 开始")
    await asyncio.sleep(delay)
    print(f"{time.strftime('%H:%M:%S')} {name} 结束（等了 {delay} 秒）")

async def main():
    # task A 等 2 秒，task B 等 1 秒
    # 如果是串行，总共要 3 秒；并发执行只需 2 秒
    await asyncio.gather(task("A", 2), task("B", 1))

asyncio.run(main())

import time

# 串行版本（time.sleep 在 async 中的效果）
print("=== 串行 ===")
start = time.perf_counter()
for name, delay in [("A", 2), ("B", 1)]:
    print(f"{time.strftime('%H:%M:%S')} {name} 开始")
    time.sleep(delay)
    print(f"{time.strftime('%H:%M:%S')} {name} 结束（等了 {delay} 秒）")
print(f"串行总耗时: {time.perf_counter() - start:.1f} 秒")

import tkinter as tk
import time

root = tk.Tk()
root.title("冻结演示")
root.geometry("300x150")

def on_click():
    print("按钮被点击")
    time.sleep(3)
    print("3 秒到了")

btn = tk.Button(root, text="点我（会冻结 3 秒）", command=on_click)
btn.pack(pady=50)
root.mainloop()

import tkinter as tk

root = tk.Tk()
root.title("非阻塞演示")
root.geometry("300x150")

def delayed_action():
    print("3 秒到了")

def on_click():
    root.after(3000, delayed_action)
    print("已安排 3 秒后执行，界面不会卡")

btn = tk.Button(root, text="点我（不会冻结）", command=on_click)
btn.pack(pady=50)
root.mainloop()