In the following code, I create a base abstract class Base. I want all the classes that inherit from Base to provide the name property, so I made this property an @abstractmethod. Then I created a subclass of Base, called Base_1, which is meant to supply some functionality, but still remain abstract. There is no … Read more
When I attempt to use a static method from within the body of the class, and define the static method using the built-in staticmethod function as a decorator, like this: class Klass(object): @staticmethod # use as decorator def _stat_func(): return 42 _ANS = _stat_func() # call the staticmethod def method(self): ret = Klass._stat_func() + Klass._ANS … Read more
Consider the following: @property def name(self): if not hasattr(self, ‘_name’): # expensive calculation self._name = 1 + 1 return self._name I’m new, but I think the caching could be factored out into a decorator. Only I didn’t find one like it 😉 PS the real calculation doesn’t depend on mutable values 19 Answers 19
TypeScript 1.5 now has decorators. Could someone provide a simple example demonstrating the proper way to implement a decorator and describe what the arguments in the possible valid decorator signatures mean? declare type ClassDecorator = <TFunction extends Function>(target: TFunction) => TFunction | void; declare type PropertyDecorator = (target: Object, propertyKey: string | symbol) => void; … Read more
I am learning Redux with React and stumbled upon this code. I am not sure if it is Redux specific or not, but I have seen the following code snippet in one of the examples. @connect((state) => { return { key: state.a.b }; }) While the functionality of connect is pretty straightforward, but I don’t … Read more
Given the Python function: def a_method(arg1, arg2): pass How can I extract the number and names of the arguments. I.e., given that I have a reference to func, I want the func.[something] to return (“arg1”, “arg2”). The usage scenario for this is that I have a decorator, and I wish to use the method arguments … Read more
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. Want to improve this question? Update the question so it’s on-topic for Stack Overflow. Closed 8 years ago. Improve this question While I like to think of myself as a reasonably competent Python coder, one aspect of the language I’ve … Read more
I was looking at the Proxy Pattern, and to me it seems an awful lot like the Decorator, Adapter, and Bridge patterns. Am I misunderstanding something? What’s the difference? Why would I use the Proxy pattern versus the others? How have you used them in the past in real world projects? 13 Answers 13
I receive the warning… Experimental support for decorators is a feature that is subject to change in a future release. Set the ‘experimentalDecorators’ option `to remove this warning. … even though my compilerOptions in tsconfig.json have the following settings: “emitDecoratorMetadata”: true, “experimentalDecorators”: true, What is weird is that some random classes that use decorators do … Read more
I have a problem with the transfer of the variable insurance_mode by the decorator. I would do it by the following decorator statement: @execute_complete_reservation(True) def test_booking_gta_object(self): self.test_select_gta_object() but unfortunately, this statement does not work. Perhaps maybe there is better way to solve this problem. def execute_complete_reservation(test_case,insurance_mode): def inner_function(self,*args,**kwargs): self.test_create_qsf_query() test_case(self,*args,**kwargs) self.test_select_room_option() if insurance_mode: self.test_accept_insurance_crosseling() else: … Read more
