装饰器
装饰器格式
def costTime(func):
import time
startTime = time.time()
func()
endTime = time.time()
print("一共用了", endTime-startTime, "秒")
def func()
sum1 = 0
for i in range(1000000):
sum1+=i
costTime(func)
装饰器
- 本质是函数
- 功能是用于装饰其他函数，为其他函数附加其它功能
装饰器的原则
- 不能修改被装饰器修饰的函数的源代码
- 不能修改被装饰器修饰的函数的调用方式
装饰器储备知识
函数即变量
def fun():
pass
fun是一个变量
高阶函数
- 在不修改被装饰函数源代码的情况下为其添加功能
- 返回值中包含函数名
函数嵌套
<!--函数内部定义函数-->
def funA():
def funB():
pass
funB()
funA()
高阶函数+嵌套函数==装饰器
进化版装饰器1
import time
def func1():
time.sleep(3)
print("func1 run")
def deco(fun):
start_time = time.time()
fun()
end_time = time.time()
print("run time", end_time - start_time)
deco(func1)
完整版装饰器
import time
def timer(func): #timer(test1) func=test1
def deco(*args,**kwargs): # 这个装饰器是通用的
start_time=time.time()
func(*args,**kwargs) # run test1()
stop_time = time.time()
print("the func run time is %s" %(stop_time-start_time))
return deco
@timer #test1=timer(test1)
def test1():
time.sleep(1)
print('in the test1')
@timer # test2 = timer(test2) = deco test2(name) =deco(name)
def test2(name,age):
print("test2:",name,age)
test1()
test2("alex",22)
完整版的终极版装饰器
import time
user,passwd = 'alex','abc123'
def auth(auth_type):
print("auth func:",auth_type)
def outer_wrapper(func):
def wrapper(*args, **kwargs):
print("wrapper func args:", *args, **kwargs)
if auth_type == "local":
username = input("Username:").strip()
password = input("Password:").strip()
if user == username and passwd == password:
print("\033[32;1mUser has passed authentication\033[0m")
res = func(*args, **kwargs) # from home
print("---after authenticaion ")
return res
else:
exit("\033[31;1mInvalid username or password\033[0m")
elif auth_type == "ldap":
print("搞毛线ldap,不会。。。。")
return wrapper
return outer_wrapper
def index():
print("welcome to index page")
@auth(auth_type="local") # home = wrapper()
def home():
print("welcome to home page")
return "from home"
@auth(auth_type="ldap")
def bbs():
print("welcome to bbs page")
index()
print(home()) #wrapper()
bbs()
