python之装饰器

装饰器:　　

import time
def cal(l):
    start_time=time.time()
    res=0
    for i in l:
        time.sleep(0.1)
        res+=i
    stop_time = time.time()
    print('函数的运行时间是%s' %(stop_time-start_time))
    return res

print(cal(range(100)))

 装饰器预演:

import time
def timmer(func):
    def wrapper(*args,**kwargs):
        start_time=time.time()
        res=func(*args,**kwargs)
        stop_time = time.time()
        print('函数运行时间是%s' %(stop_time-start_time))
        return res
    return wrapper
@timmer
def cal(l):
    res=0
    for i in l:
        time.sleep(0.1)
        res+=i
    return res

res=cal(range(10))
print(res)

 高阶函数:

　　1.函数接收的参数是一个函数名
　　2.函数的返回值是一个函数名
　　3.满足上述条件任意一个,都可称之为高阶函数

例1:
import  time
def foo():
    time.sleep(1)
    print('你好啊玉哥')

def tests(func):
    start_time = time.time()
    func()
    stop_time = time.time()
    print('函数运行时间是%s'%(stop_time-start_time))
# foo()
tests(foo)

例2:
def foo1():
    print('from the foo1')
def test(func):
    return func

ress = test(foo1)
ress()

foo1 = test(foo1)
foo1()

 函数嵌套:　

def father1(auth_type):
    def son():
        def grandson():
            print('我的爷爷是%s'%auth_type)
        grandson()
    son()
father1('sqy')