1 #try except finally
2 def exe_try():
3 try:
4 print ("code started")
5 raise KeyError
6 return 1
7 except KeyError as e:
8 print ("key error")
9 return 2
10 else:
11 print ("other error")
12 return 3
13 finally:
14 print ("finally")
15 # return 4
16
17 #上下文管理器协议
18 class Sample:
19 def __enter__(self):
20 print ("enter")
21 #获取资源
22 return self
23 def __exit__(self, exc_type, exc_val, exc_tb):
24 #释放资源
25 print ("exit")
26 def do_something(self):
27 print ("doing something")
28
29 with Sample() as sample:
30 sample.do_something()
31
32 # if __name__ == "__main__":
33 # result = exe_try()
34 # print (result)
1 import contextlib
2
3 @contextlib.contextmanager
4 def file_open(file_name):
5 print ("file open")
6 yield {}
7 print ("file end")
8
9 with file_open("bobby.txt") as f_opened:
10 print ("file processing")
