# 1. 函數(shù)賦值給變量
def hello():
    print("Hello Python")

f = hello
f()

# 2. 函數(shù)作為返回值
def outer():
    def inner():
        print("內(nèi)部函數(shù)執(zhí)行")
    return inner

res = outer()
res()

def outer(num):
    # 外層局部變量
    def inner():
        # 內(nèi)層引用外層變量
        print(f"傳入數(shù)值：{num}")
    return inner

# 接收內(nèi)層函數(shù)
func = outer(100)
# 調(diào)用內(nèi)層函數(shù)
func()

def count_factory():
    cnt = 0
    def counter():
        nonlocal cnt
        cnt += 1
        print(f"當(dāng)前計(jì)數(shù)：{cnt}")
    return counter

c1 = count_factory()
c1()  # 1
c1()  # 2
c1()  # 3

import time

def timer_decorator(func):
    # 通用裝飾器，接收任意參數(shù)
    def wrapper(*args, **kwargs):
        start = time.time()
        # 執(zhí)行原函數(shù)
        res = func(*args, **kwargs)
        end = time.time()
        print(f"函數(shù)【{func.__name__}】執(zhí)行耗時(shí)：{end - start:.4f}s")
        # 返回原函數(shù)結(jié)果
        return res
    return wrapper

# 測(cè)試函數(shù)
@timer_decorator
def calc_sum(n):
    s = 0
    for i in range(n):
        s += i
    return s

calc_sum(100000)

import time
from functools import wraps

def timer_decorator(func):
    @wraps(func)
    def wrapper(*args, **kwargs):
        start = time.time()
        res = func(*args, **kwargs)
        end = time.time()
        print(f"函數(shù)【{func.__name__}】執(zhí)行耗時(shí)：{end - start:.4f}s")
        return res
    return wrapper

from functools import wraps

def log_decorator(switch=True):
    # 外層接收裝飾器參數(shù)
    def decorator(func):
        @wraps(func)
        def wrapper(*args, **kwargs):
            if switch:
                print(f"【日志】函數(shù){func.__name__}開始執(zhí)行")
            res = func(*args, **kwargs)
            return res
        return wrapper
    return decorator

# 開啟日志
@log_decorator(switch=True)
def test_func():
    print("業(yè)務(wù)邏輯執(zhí)行")

test_func()

from functools import wraps

def deco1(func):
    @wraps(func)
    def wrapper():
        print("deco1 前置")
        func()
        print("deco1 后置")
    return wrapper

def deco2(func):
    @wraps(func)
    def wrapper():
        print("deco2 前置")
        func()
        print("deco2 后置")
    return wrapper

@deco1
@deco2
def hello():
    print("核心業(yè)務(wù)執(zhí)行")

hello()

from functools import wraps

def login_auth(func):
    @wraps(func)
    def wrapper(user_token, *args, **kwargs):
        # 模擬鑒權(quán)邏輯
        if not user_token:
            return {"code": 401, "msg": "未登錄，權(quán)限不足"}
        return func(user_token, *args, **kwargs)
    return wrapper

# 模擬接口
@login_auth
def get_user_info(token):
    return {"code": 200, "data": "用戶信息數(shù)據(jù)"}

print(get_user_info(""))

from functools import wraps

def cache_decorator(func):
    cache = {}
    @wraps(func)
    def wrapper(*args):
        if args not in cache:
            cache[args] = func(*args)
        return cache[args]
    return wrapper

@cache_decorator
def fib(n):
    if n <= 2:
        return 1
    return fib(n-1) + fib(n-2)

print(fib(30))  # 首次計(jì)算，后續(xù)直接讀取緩存

from functools import wraps

def exception_catch(func):
    @wraps(func)
    def wrapper(*args, **kwargs):
        try:
            return func(*args, **kwargs)
        except Exception as e:
            print(f"【函數(shù)異?！縶func.__name__}執(zhí)行失?。簕str(e)}")
            return None
    return wrapper

@exception_catch
def divide(a, b):
    return a / b

divide(10, 0)