day14
装饰器
装饰器本质就是闭包
开放封闭原则：
扩展是开放的（增加新功能），对源码是封闭的（修改已经实现的功能）
装饰器：用来装饰的工具
作用：在不改变源代码及调用方式的基础下额外增加新的功能
应用（面试的时候）： 登录认证、日志
增加一些功能
校验用户登录的时候
面向对象
语法糖 -- 甜：@+函数名
语法糖必须放在被装饰的函数正上方
# import time
# def times(f):
# def inner():
# start_time = time.time()
# f()
# print(time.time() - start_time)
# return inner
# def foo():
# time.sleep(1)
# print('我是立业，我快！')
# foo = times(foo)
# foo()
# def wrapper(f):
# def inner(*args,**kwargs):
# f(*args,**kwargs)
# return inner
# def func(*args,**kwargs):
# print(f"这是{args,kwargs}函数")
# func = wrapper(func)
# func('alex','sir')
版一
# import time
# start_time = time.time()
# def func():
# time.sleep(1)
# print('我要飞')
# func()
# print(time.time() - start_time)
版二
# def times(f):
# start_time = time.time()
# f()
# print(time.time() - start_time)
#
# def foo():
# time.sleep(1)
# print('小明')
#
# def func():
# time.sleep(1)
# print('章超印')
# s = func
# func = times
# func(s)
# s = foo
# foo = times
# foo(s)
版三
# def times(f):
# def inner():
# start_time = time.time()
# f()
# print(time.time() - start_time)
# return inner
#
# def foo():
# time.sleep(1)
# print('小明')
# foo = times(foo)
# foo()
# def wrapper():
# def inner():
# print(1)
# return inner
# wrapper()()
# def wrapper():
# def inner(f):
# print(f)
# return inner
#
# def func():
# print('小明')
# func = wrapper()
# func('alex')
版四
# def wrapper(f):
# def inner(*args,**kwargs):
# f(*args,**kwargs)
# return inner
# def func(*args,**kwargs):
# print(f'{args,kwargs}')
# func = wrapper(func)
# func(1,2,2,3,4,5,5,a=1,b=2)
# import time
# def wrapper(f):
# def inner(*args,**kwargs):
# start_time = time.time()
# f(*args,**kwargs)
# print((time.time() - start_time))
# return inner
# def func(*args,**kwargs):
# print(f'{args,kwargs}')
# time.sleep(1)
# func = wrapper(func)
# func(1,2,3,4,54,5,a = 1, b =2)
版五
# import time
# def wrapper(f):
# def inner(*args,**kwargs):
# start_time = time.time()
# print(f(*args,**kwargs))
# return time.time() - start_time
# return inner
# @wrapper
# def func(*args,**kwargs):
# time.sleep(1)
# print(f'{args,kwargs}')
# return 'alex'
# @wrapper
# def foo(*args,**kwargs):
# time.sleep(1)
# print(f'{args,kwargs}')
# print(func(1,2,3,4,54,5,a = 1, b =2))
# print(foo(1523,2,541,5165,12,6,a='alex',b='eeeee'))
标准版
def func(a): #a是要被装饰的函数名
def foo(*args,**kwargs):
"装饰之前的操作"
ret = a(*args,**kwargs)
"装饰之后的操作"
return ret
return foo
@func
def f1(*args,**kwargs):
print(f"这是一个{args}")
return "我可以返回了"
print(f1(1,2,3,34,4,5,a=1))
博客园
# login_dic = {
# "username": None,
# "flag": False
# }
# def auth(f):
# def inner(*args,**kwargs):
# if login_dic["flag"]:
# return f()
# else:
# return login()
# return inner
# @auth
# def index():
# print(f"这是{login_dic['username']}主页")
# return "主页没有内容"
# def login():
# print("这是一个登录页面")
# user = input("username:")
# pwd = input("password:")
# if user == "baoyuan" and pwd == "baoyuan123":
# login_dic["flag"] = True
# login_dic["username"] = user
# return "登录成功!"
# else:
# return "用户名或密码错误!"
# @auth
# def comment():
# print(f"这是{login_dic['username']}评论")
#
# while not login_dic["flag"]:
# print(comment())