In the next example, we create a simple decorator example. main.py #!/usr/bin/python def enclose(fun): def wrapper(): print("**********") fun() print("**********") return wrapper def myfun(): print("myfun") enc
**kwargs)print("Something is happening after the function is called.")returnresultreturnwrapper@my...
当Python的解释器看到这个被装饰的方法时,先编译这个方法(some_function), 然后先给它赋一个名字 'some_function'. 这个方法(some_function)再被传入装饰方法(decorator function)logging_decorator中 装饰方法(decorator function)logging_decorator返回的新方法替代原来的some_function方法, 与'some_function'这个名字绑定...
def synchronized(lock): '''Synchronization decorator.''' def wrap(f): def new_function(*args, **kw): lock.acquire() try: return f(*args, **kw) finally: lock.release() return new_function return wrap # Example usage: from threading import Lock my_lock = Lock() @synchronized(my_lock...
If you read through the source code forwrapsin functools, then you saw that it uses thepartialfunction. Partial is awesome—it’ssort of like currying. It lets you create a new function from an existing function with some of the arguments predefined. Here’s a relatively trivial example that...
@log_to_file("example.log")defdebug_function():return"Debug message"debug_result=debug_function()withopen("example.log","r")asfile:log_content=file.read()print(log_content) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. ...
The previous example, using the decorator syntax: 之前的那个例子,用decorator语法表示如下: [python]view plaincopyprint?@my_shiny_new_decoratordefanother_stand_alone_function():print"Leave me alone"another_stand_alone_function()#outputs:#Before the function runs#Leave me alone#After the function runs...
Code writing should follow the open and closed principle , It stipulates that the implemented function code is not allowed to be modified , But it can be expanded . <>2. Decorator example code # Define decorators def decorator(func): def inner(): # Decorate the existing function in the in...
so it can properly replace the decorated function. In the above examples, I've replaced the original function with an object of a class that has a__call__()method. But a function object is also callable, so we can rewrite the previous example using a function instead of a class, like...
Help on function wrapper in module __main__: wrapper(*args, **kwargs) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 可以看出,原函数的原信息会被wrapper取代 如果不想其改变,那么可用内置装饰器@functools.wraps将原函数的元信息拷贝过去。