Henk-Jaap Wagenaar added the comment: You get what you should get: when you print obj.d, Obj.d, you will get: which is exactly what you expect: - in the first case, you assigned a property object to the dictionary at obj.__dict__, so that's what you get back when you run obj.d. - you defined a property on a class called d, and you get it when you run Obj.d If you run print(Obj().d) you will get a TypeError: your lambda should read: lambda self: print('called') Properties should be added to the class not the instance, see https://stackoverflow.com/questions/1325673/how-to-add-property-to-a-class-d... and https://eev.ee/blog/2012/05/23/python-faq-descriptors/ ---------- nosy: +Henk-Jaap Wagenaar _______________________________________ Python tracker https://bugs.python.org/issue31735 _______________________________________

Paul Pinterits added the comment: If we take this class: class Obj: @property def d(self): print('called') And we access Obj.d: _ = Obj.d According to the docs, the following should happen: # obj.d looks up d in the dictionary of obj d = Obj.__dict__['d'] # If d defines the method __get__(), if hasattr(d, '__get__'): # then d.__get__(obj) is invoked d.__get__(Obj) We know this doesn't happen because nothing is printed to stdout. ---------- _______________________________________ Python tracker https://bugs.python.org/issue31735 _______________________________________

Henk-Jaap Wagenaar added the comment: I do think though that "If d defines the method __get__(), then d.__get__(obj) is invoked according to the precedence rules listed below." seems to contain a mistake in that it should have d.__get__(obj, type(obj)) instead of d.__get__(obj) ---------- _______________________________________ Python tracker https://bugs.python.org/issue31735 _______________________________________