On 26/11/16 04:59, zxjhust1 wrote: > Dear tutors: > I have some questions about memory mechanism of python.
Depending on the level of detail you need this might be more appropriate to the general Python list. Implementation details are usually a bit too advanced for most readers of tutor. However if all you want are the practical details of how to utilise the memory model this list is fine. > Do the elements of the parent go into the namespace of > the subclass when we define subclass? > > As far as I'm concerned, they do go into the namespace > of the subclass. Because when we use dir(), > we can see all the elements. > But there is only one 'update' name. I'm not sure what you mean by that? Where are you getting 'update' from? > I think the function of the subclass override the parent's. Yes that's the expected behaviour. > In this situation , when we instantiate the subclass, > we just need one argument, that is to say, > the parent's update function do the work. I think you need to post some code because what you are talking about sounds like its related to a specific example which we can't see... > According to my understanding, as there is no 'super' key word, There is a form of super in Python although it works differently in v2 and v3. Which python version are you using? And both cases work differently to Java and Smalltalk. > Another quesion is about the meaning of the private variables. Again you need to be more specific. Private attributes in Python are a bit of a bodge, more of a convention than a guarantee. > What condition shall we use them? In other word, I wanna > know the purpose of introducing the private variables. Are you familiar with OOP in other languages? That will affect how we answer that question... I have to run, hopefully someone else will picjk this up in more detail. -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ http://www.amazon.com/author/alan_gauld Follow my photo-blog on Flickr at: http://www.flickr.com/photos/alangauldphotos _______________________________________________ Tutor maillist - [email protected] To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
