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Why less emphasis on private data?

time.swift at gmail.com time.swift at gmail.com
Mon Jan 8 14:08:16 EST 2007 
Wow, I got a lot more feedback than I expected!

I can see both sides of the argument, both on technical merits, and
more philosophical merits.  When I first learned C++ I felt
setters/getters were a waste of my time and extra code.  When I moved
to C# I still felt that, and with their 'Property" syntax I perhaps
felt it more.  What changed my mind is when I started placing logic in
them to check for values and throw expections or (hopefully) correct
the data. That's probably reason one why I find it weird in Python

Reason two is, as the user of a class or API I *don't care* what is
going on inside. All I want visible is the data that I can change.  The
'_' convention is nice.. I do see that.  I guess my old OOP classes are
hard to forget about. I feel that the state of an object should be
"stable" and "valid" at all times, and if its going into an unstable
state - error then, not later.  That's why I like being able to protect
parts of an instances state. If, as a provider of a calculation engine,
I let the user change the internal state of the engine, I have no
assurances that my product (the engine) is doing its job...

<shrugs>

I appreciate all the feed back and enjoyed reading the discussion. It
helps me understand why Python community has chosen the road they have.
- Thanks.
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