Class method as a decorator

decorator, python, python-decorators

Solution

You cannot use a method of the class while defining it; there is no `self` within the class nor is the class 'baked' yet to even access any class.

You can treat methods as functions to use as a decorator:

class SomeClass():
    def action(func):
        # decorate
        return wrapper

    @action
    def execute(self, req):
        # something

If `action` is defined on a base class, then you'd have to refer to the name via the base class:

class Base():
    @staticmethod
    def action(func):
        # decorate
        return wrapper

class Derived(Base):
    @Base.action
    def execute(self, req):
        # something

For Python 2, you'd have to make `action` a static method here, as otherwise you get an unbound method that'll complain you cannot call it without an instance as the first argument. In Python 3, you can leave off the `@staticmethod` decorator there, at least for the purposes of the decorator.

But note that `action` cannot then be used as a method directly; perhaps it should not be part of the class at all at that point. It is not part of the end-user API here, presumably the decorator is not used by consumers of the instances of these classes.

Problem

I have a class where I have multiple methods. I want to use one of the methods as a decorator for other methods. For this I am using following syntax: ``` @self.action def execute(self,req): ``` where action is other method in my class. But it doesn't work and throws exception as ``` name 'self' is not defined ```

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