23day
装饰器：
1、用户不执行前不调用函数，在调用的时候再执行函数
a、传函数时不加参数
user_status = False # 用户登录了就把这个改成True
def login(func):
def inner():
_username = ‘alex‘
_password = ‘abc123‘
global user_status
if user_status == False:
username = input("user:")
password = input("password:")
if username == _username and password == _password:
print("welcome login...")
user_status = True
else:
print("wrong username or password!")
if user_status:
func()
return inner
@login
def home1():
print("首页1")
@login #等值于 home2 = login（home2）
def home2():
print("首页2")
@login
def home3():
print("首页3")
home1()
home2()
home3()
b、传函数时增加参数：
注：可以使用非固定函数*args、**kwargs。当传参数给函数时，取参数。不给函数传参数，则不取
1 user_status = False # 用户登录了就把这个改成True 2 def login(func): 3 def inner(*args,**kwargs): 4 _username = ‘alex‘ 5 _password = ‘abc123‘ 6 global user_status 7 if user_status == False: 8 username = input("user:") 9 password = input("password:") 10 if username == _username and password == _password: 11 print("welcome login...") 12 user_status = True 13 else: 14 print("wrong username or password!") 15 16 if user_status: 17 func(*args,**kwargs) 18 return inner 19 @login 20 def home1(): 21 print("首页1") 22 # @login #等值于 home2 = login（home2） 23 def home2(n): 24 print("首页2",n) 25 26 def home3(): 27 print("首页3") 28 home1() 29 home2(‘3p‘) 30 home3()
c、带参数的装饰器
可在外函数与内函数之间再套一层过度函数
user_status = False # 用户登录了就把这个改成True def login(func): def outer(func): def inner(*args,**kwargs): _username = ‘alex‘ _password = ‘abc123‘ global user_status if user_status == False: username = input("user:") password = input("password:") if username == _username and password == _password: print("welcome login...") user_status = True else: print("wrong username or password!") if user_status: func(*args,**kwargs) return inner return outer @login(‘qq‘) #先执行login（‘qq‘） 再将login（‘qq‘）@到home1 def home1(): print("首页1") # @login #等值于 home2 = login（home2） def home2(n): print("首页2",n) def home3(): print("首页3") home1() home2(‘3p‘) home3()
