Python decorator within function, needs class within method?-CodePudding

Going off of How can I define decorator method inside class? and Accessing self within decorator function within a Python class, I have the following code:

class Custom():
    def __init__(self, var):
        self.var = var

    def renew(func):
        @wraps(func)
        def wrapper(self, *args, **kwargs):
            try:
                return func(*args, **kwargs)
            except:
                print('refreshing')
                self.refresh()
                return func(*args, **kwargs)
        return wrapper

    def refresh(self):
        self.var = 'refreshed'

    @renew
    def get_something(self):

        print(self.var)
        raise Exception

test = Custom('a')
test.get_something(test)

Which returns exactly what I want (pretend that the raise Exception is a expiration timeout, where var expires after some time, am just forcing an Exception here):

a
refreshing
refreshed
---------------------------------------------------------------------------
Exception                                 Traceback (most recent call last)
...

However, is there any way to not require the class instance test to be in the class method, namely test.get_something(test) -> test.get_something()? Or is this best practice? What is the best way to handle something like this?

CodePudding user response：

In your renew decorator you are not passing instance parameter when calling the decorated function from wrapper. You need to pass it as

func(self, *args, **kwargs)

Once you correct the invocation call inside wrapper, you no longer need to pass class instance object when invoking your decorated function. So test.get_something() would work now.