On 19/08/17 05:26, boB Stepp wrote: > related methods needs to share the same values and a class would tidy > this up nicely without the need for any globals or needless passing of > the exact same values around as parameters/arguments.
Indeed, but its important to remember that class attributes are in effect just global data confined to a smaller context, and they share many of the same issues of global data. Functions(methods) can (and usually do) change the data as a side effect of being called, without it being obvious that self.foo() is modifying say, self.bar and self.baz, internally. The advantage of a class is that at least it constrains the candidate culprits to other members of our class, but the underlying problem of changes by side-effect remains, even if reduced. Classes don't remove the problems with globals, they just limit the damage. >> possible, and hence make the program less complex. OO design tries to >> encapsulate the coupling within (hopefully) a single class, but it does >> nothing to reduce the coupling or complexity. exactly so. > I really enjoyed reading this brief article. He explained things > rather clearly. Kent was a long time member of this group for many years. I think he left just about the same time Steve appeared. -- 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 - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
