[PYTHON] Get the class name where the method is defined in the decorator

A memo when I had a hard time getting the class name when logging the method execution time

Thing you want to do

I want to display the class name and method name when logging with a decorated method to find out which method is running at what time

try1

Implementation content

Try to decorate normally

def deco(func):
    def inner(self, *args, **kwargs):
        result = func(self, *args, **kwargs)
        print 'class: %s, method: %s' % (
            func.im_class.__name__,
            func.__name__)
        #Logging process
        return result
    return inner

Result: error

func was passed as a function and didn't have im_class. For this reason, I could get the method name, but not the class name.

try2

Implementation content

Get the class name from self.

def deco(func):
    def inner(self, *args, **kwargs):
        result = func(self, *args, **kwargs)
        print 'class: %s, method: %s' % (
            self.__class__.__name__,
            func.__name__)
        #Logging process
        return result
    return inner

Result: error?

NG because the subclass name will be returned when inheriting

try3

Implementation content

Decorate the class.

def deco_cls(cls):
    def deco_method(func):
        def inner(self, *args, **kwargs):
            result = func(self, *args, **kwargs)
            print 'class: %s, method: %s' % (
                cls.__name__,
                func.__name__)
            #Logging process
            return result
        return inner

    for name, method in cls.__dict__.items():
        if name == 'target_func':
            setattr(cls, name, deco_method(method))
    return cls

Result: OK

It is compared as target_func, but in the version actually used, the target method name was prepared as a tuple and compared. If you want to specify the target method clearly, you can also use the following method.

def deco_cls(cls):
    def deco_method(func):
        def inner(self, *args, **kwargs):
            result = func(self, *args, **kwargs)
            print 'class: %s, method: %s' % (
                cls.__name__,
                func.__name__)
            #Logging process
            return result
        return inner

    for name, method in cls.__dict__.items():
        if hasattr(method, 'set_logger'):
            setattr(cls, name, deco_method(method))
    return cls

def set_logger_wrapper(func):
    func.set_logger = True
    return func