day20-python之装饰器

1.装饰器

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 import time
 4 def cal(l):
 5     start_time=time.time()
 6     res=0
 7     for i in l:
 8         time.sleep(0.1)
 9         res+=i
10     stop_time = time.time()
11     print('函数的运行时间是%s' %(stop_time-start_time))
12     return res
13  
14 
15 
16 print(cal(range(100)))
17 
18 
19 def index():
20     pass
21 
22 def home():
23     pass

2.装饰器预演

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 import time
 4 def timmer(func):
 5     def wrapper(*args,**kwargs):
 6         start_time=time.time()
 7         res=func(*args,**kwargs)
 8         stop_time = time.time()
 9         print('函数运行时间是%s' %(stop_time-start_time))
10         return res
11     return wrapper
12  
13 def timmer1(func):
14     def wrapper(*args,**kwargs):
15         start_time = time.time()
16         res = func(*args,**kwargs)
17         stop_time = time.time()
18         print('函数运行时间是%s' %(stop_time-start_time))
19         return res
20     return wrapper()
21 
22 
23 @timmer
24 def cal(l):
25     res=0
26     for i in l:
27         time.sleep(0.1)
28         res+=i
29     return res
30 
31 res=cal(range(20))
32 print(res)
33 
34 
35 def index():
36     pass
37 
38 def home():
39     pass

3.高阶函数

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 '''
 4 高阶函数定义:
 5 1.函数接收的参数是一个函数名
 6 2.函数的返回值是一个函数名
 7 3.满足上述条件任意一个,都可称之为高阶函数
 8 '''
 9 # import time
10 # def foo():
11 #     time.sleep(3)
12 #     print('你好啊林师傅')
13 
14 # def test(func):
15 #     # print(func)
16 #     start_time=time.time()
17 #     func()
18 #     stop_time = time.time()
19 #     print('函数运行时间是  %s' % (stop_time-start_time))
20 # foo()
21 # test(foo)
22 
23 # def foo():
24 #     print('from the foo')
25 # def test(func):
26 #     return func
27 # res=test(foo)
28 # # print(res)
29 # res()
30 
31 
32 import time
33 def foo():
34     time.sleep(3)
35     print('来自foo')
36 
37 #不修改foo源代码
38 #不修改foo调用方式
39 
40 #多运行了一次，不合格
41 # def timer(func):
42 #     start_time=time.time()
43 #     func()
44 #     stop_time = time.time()
45 #     print('函数运行时间是  %s' % (stop_time-start_time))
46 #     return func
47 # foo=timer(foo)
48 # foo()
49 
50 
51 #没有修改被修饰函数的源代码，也没有修改被修饰函数的调用方式，但是也没有为被修饰函数添加新功能
52 # def timer(func):
53 #     start_time=time.time()
54 #     return func
55 #     stop_time = time.time()
56 #     print('函数运行时间是  %s' % (stop_time-start_time))
57 #
58 # foo=timer(foo)
59 # foo()
60  

4.函数嵌套

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 # def bar():
 4 #     print('from bar')
 5 #
 6 # def foo():
 7 #     print('from foo')
 8 #     def test():
 9 #         pass
10 
11 def father(auth_type):
12     # print('from father %s' %name)
13     def son():
14         # name='linhaifeng_1'
15         # print('我的爸爸是%s' %name)
16         def grandson():
17             print('我的爷爷是%s' %auth_type)
18         grandson()
19     # print(locals())
20     son()
21 # father('linhaifeng')
22 father('filedb')

5.加上返回值

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 import time
 4 def timmer(func): #func=test
 5     def wrapper():
 6         start_time=time.time()
 7         res=func() #就是在运行test()
 8         stop_time = time.time()
 9         print('运行时间是%s' %(stop_time-start_time))
10         return res
11     return wrapper
12 
13 @timmer #test=timmer(test)
14 def test():
15     time.sleep(3)
16     print('test函数运行完毕')
17     return '这是test的返回值'
18 
19 # res=test()  #就是在运行wrapper
20 # print(res)