1 第一种；未使用@符号
2 def a_new_decorator(a_func): # a_func = a_function_requiring_decoration
3 def wrapTheFunction():
4 """the doc for wrapTheFunction"""
5 print("I am doing some boring work before executing a_func()")
6 a_func() # a_function_requiring_decoration()
7 print("I am doing some boring work after executing a_func()")
8
9 return wrapTheFunction
10
11 def a_function_requiring_decoration():
12 """Hey you! Decorate me!"""
13 print("I am the function which needs some decoration to remove my foul smell")
14
15 a_function_requiring_decoration()
16 # I am the function which needs some decoration to remove my foul smell
17 a_function_requiring_decoration = a_new_decorator(a_function_requiring_decoration) #注意这种写法，相当于是执行函数后并返回一个函数，然后把返回的函数赋值给一个变量
18 a_function_requiring_decoration()
19 # I am doing some boring work before executing a_func()
20 # I am the function which needs some decoration to remove my foul smell
21 # I am doing some boring work after executing a_func()
22
23 第二种，使用@符号
24 def a_new_decorator(a_func): # a_func = a_function_requiring_decoration
25 def wrapTheFunction():
26 """the doc for wrapTheFunction"""
27 print("I am doing some boring work before executing a_func()")
28 a_func() # a_function_requiring_decoration()
29 print("I am doing some boring work after executing a_func()")
30
31 return wrapTheFunction
32
33 # a_function_requiring_decoration = a_new_decorator(a_function_requiring_decoration)
34 @a_new_decorator # @这句这个等价于上面的那句
35 def a_function_requiring_decoration():
36 """Hey you! Decorate me!"""
37 print("I am the function which needs some decoration to remove my foul smell")
38
39 a_function_requiring_decoration()
40 # I am doing some boring work before executing a_func()
41 # I am the function which needs some decoration to remove my foul smell
42 # I am doing some boring work after executing a_func()
43
44 第三种：获取原来函数的信息等
45 from functools import wraps
46
47 def a_new_decorator(a_func): # a_func = a_function_requiring_decoration
48 @wraps(a_func) #注意这个的写法
49 def wrapTheFunction():
50 """the doc for wrapTheFunction"""
51 print("I am doing some boring work before executing a_func()")
52 a_func() # a_function_requiring_decoration()
53 print("I am doing some boring work after executing a_func()")
54
55 return wrapTheFunction
56
57 @a_new_decorator # a_function_requiring_decoration = a_new_decorator(a_function_requiring_decoration)
58 def a_function_requiring_decoration():
59 """Hey you! Decorate me!"""
60 print("I am the function which needs some decoration to remove my foul smell")
61
62 a_function_requiring_decoration()
63
64 print(a_function_requiring_decoration.__name__) # a_function_requiring_decoration
65
66 若不加上@wraps(a_func)，执行print(a_function_requiring_decoration.__name__)，返回的结果是wrapTheFunction
67
68 第四种：传参
69 from functools import wraps
70 def logit(logfile='out.log'): # 外面又多了一层函数
71 def loggint_decorator(func):
72 @wraps(func) # 注意这个的位置
73 def wrapped_function(*args,**kwargs):
74 log_string = func.__name__ + "was called"
75 print(log_string)
76 with open(logfile,'a') as opened_file:
77 opened_file.write(log_string+'
')
78 return func(*args,**kwargs)
79 return wrapped_function
80 return loggint_decorator
81
82 @logit() # 注意后面加上的有括号，需要传参时才加上括号，并且在外面又套了一个函数，未指定参数使用默认值，
83 def myfunc1():
84 print('myfunc1')
85
86 # myfunc1()
87
88 @logit(logfile='func2.log') # 指定参数
89 def myfunc2():
90 print('myfunc2')
91
92 myfunc2()
93
94
95 第五种：装饰器类
96 from functools import wraps
97
98 class logit(): # 没有object，说明是py3类的写法
99
100 def __init__(self,logfile='out.log'):
101 self.logfile = logfile
102
103 def __call__(self, func): # 注意这个的写法
104 @wraps(func)
105 def wrapped_function(*args,**kwargs):
106 log_string = func.__name__ + " was called!"
107 print(log_string)
108 with open(self.logfile,'a') as opened_file:
109 opened_file.write(log_string+"
")
110 self.notify()
111 return func(*args,**kwargs)
112 return wrapped_function
113
114 def notify(self):
115 print('notify')
116
117 @logit()
118 def myfunc1():
119 print('myfunc1')
120
121 myfunc1()
122
123 第六种：装饰器子类
124 from functools import wraps
125
126 class logit():
127
128 def __init__(self,logfile='out.log'):
129 self.logfile = logfile
130
131 def __call__(self, func):
132 @wraps(func)
133 def wrapped_function(*args,**kwargs):
134 log_string = func.__name__ + " was called!"
135 print(log_string)
136 with open(self.logfile,'a') as opened_file:
137 opened_file.write(log_string+"
")
138 self.notify()
139 return func(*args,**kwargs)
140 return wrapped_function
141
142 def notify(self):
143 print('notify')
144
145 @logit()
146 def myfunc1():
147 print('myfunc1')
148
149 # myfunc1()
150
151 class email_logit(logit):
152 '''
153 一个logit的实现版本，可以在函数调用时发送email给管理员
154 '''
155 def __init__(self,email="admin@myproject.com",*args,**kwargs):
156 self.email = email
157 super().__init__(*args,**kwargs) #py3子类继承父类的写法
158
159 def notify(self):
160 print('发送邮件')
161
162 @email_logit()
163 def myfunc2():
164 print('myfunc2')
165
166 myfunc2()