Recommendation for Object-Oriented systems to study

[Ankush Thakur]

On Monday, May 30, 2016 at 5:04:27 AM UTC+5:30, Gregory Ewing wrote:
> Alan Evangelista wrote:
> 
> > if the interest is learning OOP concepts (and not OOP in Python), IMHO 
> > Java is better.
> 
> The problem with this is that if you're not careful you'll
> end up learning a lot of cruft that is irrelevant to Python.
> There's no clear distinction in Java between things that
> are essential to OO and things that are only there to
> support its rigid statically-typed view of the world.
> 
> > - Java forces everything to be implemented in OO model (classes)
> 
> Actually, it doesn't do that any more than Python does.
> Static methods are really stand-alone functions; they just
> happen to live in the namespace of a class. In other words,
> all Java does in this area is confuse things by conflating
> modules with classes.
> 
> > - Java widely uses interfaces and abstract classes. Python has not the 
> > concept of interface, as it favors EAFP
> > and duck typing instead of creating base classes which establish 
> > contracts.
> 
> And this is one of the important things to understand if
> you want to write Python programs, rather than Java programs
> encoded in Python.
> 
> > Python also allows multiple inheritance,
> > which is *usually* a bad idea, unless the base classes are interfaces.
> 
> Actually the best use of multiple inheritance in Python is
> to factor out *functionality*, more or less the opposite
> of what Java allows. In fact, that goes for inheritance of
> any kind; you only need it if you want to share functionality
> from the base class. This is very different from Java,
> where considerations of static interface checking dominate
> everything.
> 
> > - In Java, interface/implementation separation is *usually* a bigger 
> > concern (eg getters and setters
> > are common in Java code, rare in Python code) .
> 
> That's because you don't *need* them in Python, since you
> can always turn an attribute into a property at any time
> without affecting calling code. You can't do that in Java,
> which is the only reason you see so many getters and setters.
> If you think you might ever need them, you have to start
> out with them from the beginning.
> 
> So in summary, I wouldn't recommend learning Java as a
> precursor to learning Python OO. You'll just confuse yourself
> and pick up a lot of bad habits that you'll have to unlearn
> later.
> 
> -- 
> Greg

Thanks, Greg. To everyone involved in this Java tangent: thankfully I have some taste of object-oriented programming in Java. Personally, I much prefer Python's dynamic approach, although sometimes it's a pain to find that all the patterns "wisdom" you collected is useless. :D

~~Ankush