作者： renho

import asyncio
import time

print("\n\n=== 2. 异步模式开始 (请注意观察心跳) ===")

# 这是一个背景任务，模拟 UI 动画或者心跳检测
async def background_heartbeat():
    while True:
        print("   💓 (背景任务) 咚-咚-咚... 程序还活着！")
        await asyncio.sleep(0.3) # 每0.3秒跳动一次

# 异步生成器
async def async_stream():
    for i in range(3):
        print(f"🔄 (生成器内部) 正在用力下载第 {i+1} 个包...")
        # 【挂起】告诉 Python：我要等1秒，这期间你去处理那个“心跳”任务吧
        await asyncio.sleep(1) 
        yield f"📦 包 {i+1} 下载完成"

async def main():
    # 1. 启动背景心跳任务
    task = asyncio.create_task(background_heartbeat())

    start_time = time.time()

    # 2. 开始 Async For 循环
    # 关键点：每次在这里“等”数据的时候，上面的 background_heartbeat 就会插队运行
    async for data in async_stream():
        print(f"✅ 主程序收到: {data}\n")

    # 停止心跳任务
    task.cancel()
    print(f"=== 异步模式结束，总耗时: {time.time() - start_time:.2f}秒 ===")

# 运行
asyncio.run(main())

集合

# set

s1 = {1, 2, 3, 4}
print(type(s1))
print(s1)
s1.add(5)
s1.add(6)
print(s1)
s2 = {5, 6, 7, 8}
s3 = s1 | s2
print(s3)
s3.remove(3)
s3.discard(4)
print(s3)

s4 = {s for s in range(10, 20)}
print(s4)


t0 = (1, 2, 3, 4)
print(t0)


m = {
    "a": "a",
    "b": "",
    "c": None
}

print(m.get("a"))
print(m.get("b"))
print(m.get("c"))
print(m.get("d"))


print("--------")
print(m.get("a", "aa"))
print(m.get("b", "bb"))
print(m.get("c", "cc"))
print(m.get("d", "dd"))
print("--------")
print(m.get("a") if m.get("a") else "aa")
print(m.get("b") if m.get("b") else "bb")
print(m.get("c") if m.get("c") else "cc")
print(m.get("d") if m.get("d") else "dd")

内置函数

################## zip
list0 = ["a", "b", "c"]
list1 = [1, 2, 3]
list2 = ["A", "B", "C"]

result = zip(list0, list1, list2)
print(str(result))
# for item in result:
#     print(item)
list3 = list(result)
print(list3)
print('----------')
print(locals())
print(globals())


################## sorted
list0 = ["a", "abb", "adddd", "accc"]
result = sorted(list0, key=lambda k: len(k))
print(result)

################## filter
result = filter(lambda s: "adddd" == s, list0)
print(list(result))

################## map
result = map(lambda i : i + i, list0)
print(list(result))

################## reduce
s0 = {0, 1, 2, 3}
s1 = {1, 2, 3}
from functools import reduce
result = reduce(lambda a, b: a | b, [s0, s1])

print('67' in '67@1@dhxy')

################## zip
list0 = ["a", "b", "c"]
list1 = [1, 2, 3]
list2 = ["A", "B", "C"]

result = zip(list0, list1, list2)
print(str(result))
# for item in result:
#     print(item)
list3 = list(result)
print(list3)
print('----------')
print(locals())
print(globals())


################## sorted
list0 = ["a", "abb", "adddd", "accc"]
result = sorted(list0, key=lambda k: len(k))
print(result)

################## filter
result = filter(lambda s: "adddd" == s, list0)
print(list(result))

################## map
result = map(lambda i : i + i, list0)
print(list(result))

################## reduce
s0 = {0, 1, 2, 3}
s1 = {1, 2, 3}
from functools import reduce
result = reduce(lambda a, b: a | b, [s0, s1])
print(result)