-------------------------------------------- On Wed, 10/23/13, Steven D'Aprano <st...@pearwood.info> wrote:
Subject: Re: [Tutor] Beginner Question To: tutor@python.org Date: Wednesday, October 23, 2013, 5:27 AM On Tue, Oct 22, 2013 at 04:25:59PM +0200, Sven Hennig wrote: > Hello, I would like to learn a programming language and have decided to use > Python. I have some programming experience and doing well in Python. What > really causes me problems is OOP. > I'm just dont get it... I'm missing a really Practical example. In every > book I've read are the examples of such Class Dog and the function is bark. Has > anyone an OOP example for me as it is really used in real code, so I can > better understand the concept? I do not know why this is so hard for me. I can sympathise. You wouldn't believe how long it took me to really grok object-oriented programming. I just didn't get it, until I started thinking of OOP as being just syntax for keeping functions (called "methods") close to the data they belong with. There is more to OOP than that, but that was my first step: OOP helps you keep your functions close to the data they work with. <snip> That's all you need to know to start using object oriented programming in Python! Many operations are implemented as methods, for instance strings have upper and lower methods, lists have append and remove methods, and many more. You'll soon learn the operations like len() that aren't methods, but old-school functions. ==> This reminded me of a text by Guido van Rossum (I can't find the original page): http://effbot.org/pyfaq/why-does-python-use-methods-for-some-functionality-e-g-list-index-but-functions-for-other-e-g-len-list.htm So the built-in 'len()' is *really* a function, but calls to len() implemented by __len__ are method calls *disguised* as function calls? I sometimes find it easier to write calls to special methods the "normal" way, e.g. instead of "x + y" just write it like "x.__add__(y)" This makes special methods more like other methods and therefore easier to understand, to me at least. Albert-Jan PS: sorry about the lack of quoting. Yahoo mail was "upgraded" and now all sorts of stuff stops working, times out, etc. _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
