————————装饰器=高阶函数+嵌套函数——————————

高阶函数：1、把一个函数名当做实参传递给另一个函数；2、返回值中包含函数名

def func1():
    print("this is func1")

def test(func):
    print(func)
    func()

test(func1)

输出结果：

装饰器：为其他函数添加附加功能，不改变原函数代码及调用方式

import time

def bar():
    time.sleep(2)
    print("this is bar")

def test1(func1):
    print(func1)
    return func1

bar = test1(bar)
bar()

不改变调用方式，未添加新功能---------

import time
def deco(func):
    start_time = time.time()
    return  func
    stop_time = time.time()
    print(‘Running time is %s:‘%(stop_time-start_time))

def test1():
    time.sleep(2)
    print("this is test1")
def test2():
    time.sleep(2)
    print("this is test2")

test1 = deco(test1)
test1()
test2 = deco(test2)
test2()

运行结果：

不改变调用方式，添加新功能---------

import time
def timer(func):
    def deco():
        start_time = time.time()
        func()
        stop_time = time.time()
        print(‘Running time is %s:‘%(stop_time-start_time))
    return deco

def test1():
    time.sleep(2)
    print("this is test1")
def test2():
    time.sleep(3)
    print("this is test2")

test1 = timer(test1)
test1()
test2 = timer(test2)
test2()

 运行结果：

使用@符号-----------

import time
def timer(func):
    def deco():
        start_time = time.time()
        func()
        stop_time = time.time()
        print(‘Running time is %s:‘%(stop_time-start_time))
    return deco
@timer
def test1():
    time.sleep(2)
    print("this is test1")
def test2():
    time.sleep(3)
    print("this is test2")

test1()
test2 = timer(test2)
test2()

原函数带有参数-----------

import time
def timer(func):
    def deco(*arg,**kwarg):
        start_time = time.time()
        func(*arg,**kwarg)
        stop_time = time.time()
        print(‘Running time is %s:‘%(stop_time-start_time))
    return deco
@timer
def test1():
    time.sleep(2)
    print("this is test1")
@timer  #test2 = timer(test2)
def test2(name,age):
    time.sleep(1)
    print("this is test2:",name,age)

test1()
test2(‘lili‘,18)

运行结果：

原函数有返回值----------

user,passwd = ‘lili‘,‘abc‘
def auth(func):
    def wrapper(*args,**kwargs):
        username = input("Username:").strip()
        password = input("Passwd:").strip()

        if user == username and passwd ==password:
            print("\033[32;1mUser has passed authenticatiom\033[0m")
            return func(*args,**kwargs)
        else:
            exit("\033[31;1mInvalid username or password\033[0m")
    return wrapper
@auth
def page1():
    print("this is page1")
    return "from page1"
@auth
def page2():
    print("this is page2")
@auth
def page3():
    print("this is page3")


print(page1())

运行结果：

装饰器带参数-------------

user,passwd = ‘lili‘,‘abc‘
def auth(auth_type):
    print("auth_arge:",auth_type)
    def outer_wrapper(func):
        def wrapper(*args,**kwargs):
            if auth_type == ‘p1‘:
                username = input("Username:").strip()
                password = input("Passwd:").strip()

                if user == username and passwd ==password:
                    print("\033[32;1mUser has passed authenticatiom\033[0m")
                    return func(*args,**kwargs)
                else:
                    exit("\033[31;1mInvalid username or password\033[0m")
            elif auth_type == ‘p2‘:
                print(‘p2 pass‘)
        return wrapper
    return outer_wrapper

@auth(auth_type = "p1")
def page1():
    print("this is page1")
    return "from page1"
@auth(auth_type = "p2")
def page2():
    print("this is page2")

print(page1())
page2()

运行结果：

Python 3.x--装饰器