Looking for a good introduction to object oriented programming with Python

[Steven D'Aprano]

On Sun, 05 Aug 2012 19:44:31 -0700, alex23 wrote:

> I think you've entirely missed the point of Design Patterns.

Perhaps I have. Or perhaps I'm just (over-)reacting to the abuse of 
Patterns:

http://c2.com/cgi/wiki?DesignPatternsConsideredHarmful

or maybe I'm just not convinced that Design Patterns as described by the 
Go4 are as important and revolutionary as so many people seem to believe:

http://perl.plover.com/yak/design/

or that they are a crutch for underpowered languages:

http://c2.com/cgi/wiki?AreDesignPatternsMissingLanguageFeatures

I haven't read the Gang of Four book itself, but I've spent plenty of 
time being perplexed by over-engineered, jargon-filled code, articles, 
posts and discussions by people who use Design Patterns as an end to 
themselves rather than a means to an end. (Singleton is notoriously bad 
in that way.)

On the other hand, as I think I've stated before, the design patterns 
themselves aren't *necessarily* bad. They're just problem solving 
techniques and common idioms.

I think that as languages get more powerful, "Design Patterns" just 
become language features, and people stop talking about them. Nobody 
talks about Function Pattern, but everyone uses it. In Python, we don't 
talk about the Iterator Pattern. We just use iterators.


> No one claims that the Go4 DP book introduced Builders, Singletons,
> Facades. The point was to identify _and name_ such patterns, so
> programmers could actually talk about repeated behaviour.

I'm pretty sure that people could talk about good coding design before 
the Gof4. As you say, they didn't invent the patterns. So people 
obviously wrote code, and talked about algorithms, without the Gof4 
terminology.

I don't think that "Memento Pattern" is any more clear than "save and 
restore".

When you have a few standard patterns, everyone can know what they are. 
When you start getting into multiple dozens, it's not so clear to me that 
they are all *standard* any more.

http://c2.com/cgi/wiki?CategoryPattern

And the ever-finer distinctions between variations on patterns. Without 
looking them up, what are the difference between Default Visitor, 
Extrinsic Visitor, Acyclic Visitor, Hierarchical Visitor, Null Object And 
Visitor, and regular old Visitor patterns? -- and no, I did not make any 
of them up.



-- 
Steven