一：编写函数，（函数执行的时间用time.sleep(n)模拟）
def func():
import time
start = time.time()
time.sleep(3)
end = time.time()
print(end - start)
func()
二：编写装饰器，为函数加上统计时间的功能
def outter(func1):
def func():
import time
start = time.time()
func1()
end = time.time()
print(end - start)
return func
@outter
def func1():
print(100)
func1()
三：编写装饰器，为函数加上认证的功能
def outter(func1):
def func(*args,**kwargs):
user = input('请输入账号：').strip()
pwd = input('请输入密码：').strip()
if user == 'egon' and pwd == '123':
print('登陆成功')
func1()
else:
print('登陆失败')
return None
return func
@outter
def func2():
print('登录程序执行了')
func2()
四：编写装饰器，为多个函数加上认证的功能（用户的账号密码来源于文件），要求登录成功一次，后续的函数都无需再输入用户名和密码
注意：从文件中读出字符串形式的字典，可以用eval('{"name":"egon","password":"123"}')转成字典格式
def outter(func):
def wrapper():
global login
if not login:
user = input('请输入账号：').strip()
pwd = input('请输入密码：').strip()
with open('tank.txt','r',encoding='utf-8') as f:
for line in f:
d1 = eval(line.strip())
if user == d1['name'] and pwd == d1['password']:
print('登陆成功')
login = True
func()
break
else:
print('登陆失败')
else:
func()
return wrapper
@outter
def fun1():
print('提现功能')
@outter
def fun2():
print('转账功能')
@outter
def fun3():
print('特殊功能')
login = False
fun1()
fun2()
fun3()
五：编写装饰器，为多个函数加上认证功能，要求登录成功一次，在超时时间内无需重复登录，超过了超时时间，则必须重新登录
def outter(func):
def wrapper():
global login
if os.path.exists('login.txt'):
with open('login.txt','r',encoding='utf-8') as f1:
l = f1.read()
if float(l) < time.time():
login = False
if not login:
if os.path.exists('login.txt'):
os.remove('login.txt')
user = input('请输入账号：').strip()
pwd = input('请输入密码：').strip()
with open('tank.txt','r',encoding='utf-8') as f:
for line in f:
d1 = eval(line.strip())
if user == d1['name'] and pwd == d1['password']:
print('登陆成功')
with open('login.txt','w',encoding='utf-8') as f5:
f5.write(str(time.time() + 10))
login = True
func()
break
else:
print('登陆失败')
else:
func()
return wrapper
@outter
def fun1():
print('提现功能')
@outter
def fun2():
print('转账功能')
@outter
def fun3():
print('特殊功能')
login = False
import os,time
fun1()
fun2()
time.sleep(11)
fun3()
六：选做题
思考题（选做），叠加多个装饰器，加载顺序与运行顺序，可以将上述实现的装饰器叠加起来自己验证一下
def deco1(func):
def swapper():
func()
print(1)
return swapper
def deco2(func):
def swapper():
func()
print(2)
return swapper
def deco3(func):
def swapper():
func()
print(3)
return swapper
@deco1 # index=deco1(deco2.wrapper的内存地址)
@deco2 # deco2.wrapper的内存地址=deco2(deco3.wrapper的内存地址)
@deco3 # deco3.wrapper的内存地址=deco3(index)
def index():
pass
index()
