装饰器进阶
2019 年 7 月 24 日
老师上课主要是两个内容
有参装饰器
login_dic = {
"username": None,
"flag": False
}
# 正确的案例
msg = """
QQ
微信
抖音
邮箱
请输入您要选择登陆的app:
"""
chose = input(msg).upper()
def auth(argv):
def wrapper(func):
def inner(*args,**kwargs):
if login_dic["flag"]:
func(*args,**kwargs)
else:
if argv == "QQ":
print("欢迎登陆QQ")
user = input("username:")
pwd = input("password:")
if user == "alex" and pwd == "alex123": # qq
login_dic["flag"] = True
login_dic["username"] = user
func(*args,**kwargs)
else:
print("用户名或密码错误!")
elif argv == "微信":
print("欢迎登陆微信")
user = input("username:")
pwd = input("password:")
if user == "1351101501" and pwd == "alex": # 微信
login_dic["flag"] = True
login_dic["username"] = user
func(*args, **kwargs)
else:
print("用户名或密码错误!")
elif argv == "抖音":
print("来了,老弟!")
user = input("username:")
pwd = input("password:")
if user == "alexdsb" and pwd == "alex": # 抖音
login_dic["flag"] = True
login_dic["username"] = user
func(*args, **kwargs)
else:
print("用户名或密码错误!")
else:
print("欢迎登陆dab邮箱")
user = input("username:")
pwd = input("password:")
if user == "alexdsb@dsb.com" and pwd == "alex": # 邮箱
login_dic["flag"] = True
login_dic["username"] = user
func(*args, **kwargs)
else:
print("用户名或密码错误!")
return inner
return wrapper
@auth("QQ")
def foo():
print("这是一个被装饰的函数")
# wrapper = auth(chose)
# foo = wrapper(foo)
foo()
多个装饰器装饰一个函数
def wrapper1(func):
def inner1(*args,**kwargs):
print(1)
func(*args,**kwargs)
print(11)
return inner1
def wrapper2(func):
def inner2(*args,**kwargs):
func(*args,**kwargs)
print(22)
return inner2
def wrapper3(func):
def inner3(*args,**kwargs):
print(3)
func(*args,**kwargs)
print(33)
return inner3
@wrapper1
@wrapper2
@wrapper3
def foo():
print(8)
foo = wrapper2(foo) # foo = inner2
foo = wrapper3(foo) # inner3 = wrapper3(inner2)
foo = wrapper1(foo) #inner1 = wrapper1(inner)
foo()
被装饰的函数正上方有多个装饰器,先执行离被装饰函数最近的装饰器
一开始是正着来,输出最后一行后然后反着来
先执行离被装饰的函数最近的语法糖
# 小技巧:进入装饰器从上往下,走到最会一个装饰器执行被装饰的函数,退出装饰器从下往上走
宝哥如是说
