Basic knowledge of Python programming practice _002

Practice content:

(1) function adorner.
(2) using the Magic Method __call__, a class is implemented as an adorner .
(3) using the Magic method __enter__ and __exit__, a class is implemented so that it can provide context management functions for functions.

1. Function Adorner

1 __author__='Orcsir'2  fromFunctoolsImportWraps, Update_wrapper3 Import Time4 5 6 #implement a function as an adorner7 defTimeit (func):8 @wraps (func)9     def_wrapper (*args, * *Kwargs):Ten         Print("Inject Some code before func run.") One  Aret = func (*args, * *Kwargs) -  -         Print("Inject Some code after func run.") the  -         returnret -  -     return_wrapper +  -  + @timeit A defFunc (*args, * *Kwargs): at     Print("func start processing.") -Time.sleep (2)#Simulated processing time -     Print("func end processing.") -     returnNone -  - #Test inFunc (.)

2. Use the Magic method __call__ to implement a class as an adorner

1 __author__='Orcsir'2  fromFunctoolsImportWraps, Update_wrapper3 Import Time4 5 #implement a class as an adorner6 classTimeit:7     def __init__(self, wrapped):8Self.__wrapped=Wrapped9 Wraps (wrapped) (self)Ten  One     def __call__(Self, *args, * *Kwargs): A         Print("Inject Some code before func run.") -ret = self.__wrapped(*args, * *Kwargs) -         Print("Inject Some code after func run.") the         returnret -  -  - @TimeIt + defFunc (*args, * *Kwargs): -     Print("func start processing.") +Time.sleep (2)#Simulated processing time A     Print("func end processing.") at     returnNone -  - #Test -Func ()

3. Using the Magic method __enter__ and __exit__, implement a class that enables it to provide context management functionality for functions

1 __author__='Orcsir'2  fromFunctoolsImportWraps, Update_wrapper3 Import Time4 5 #implement a class that provides context management functionality for a function6 classContextmage4func:7     def __init__(Self, func):8Self.__func=func9 Ten     def __enter__(self): One         Print("prepares the environment for the Func function's run.") A         returnSelf.__func -  -     def __exit__(self, exc_type, Exc_val, EXC_TB): the         Print("when the Func function exits or an exception occurs, do some cleanup work.") -  -  - defFunc (*args, * *Kwargs): +     Print("func start processing.") -Time.sleep (2)#Simulated processing time +     Print("func end processing.") A     returnNone at  - #Test - With Contextmage4func (func): -Func (1, 2) - Print("~~~~~~~~~~~~~~~~~~~~~~") - With Contextmage4func (func) as F: inF (1, 2)

Basic knowledge of Python programming practice _002