class level properties

[Peter Otten]

Charles D Hixson wrote:

> Peter Otten wrote:
>> Charles D Hixson wrote:
>>
>>   
>>> I want a hundred or so read-only variables, and I'm not sure the best
>>> way to achieve it.
>>>     
>>
>> What do you really want to do? I recommend that you forget about bondage
>> and rely upon displine:
>>
>> class Test(object):
>>     """Never change an attribute with an uppercase name."""
>>     SIMPLE = "simple example working"
>>
>> Now that was easy...
>>
>> Peter
>>
>>   
> What I'm doing it translating Java code which has a large number of
> "public static final (type)" variables.

Ah, Java, the class is an artefact of the language then, and my example
becomes

SIMPLE = "simple example working"

> As to your answer ... yes, and with good discipline you can write object
> oriented code in C and never need a garbage collector.  It's *not* a
> good answer.  Before I'd chose that one, I'd make it necessary to

Hmm, if you were to choose between a Java dialect without garbage collection
or without the 'final' keyword, would you throw a coin?

> instantiate the class before testing the value of it's constants.  It's
> just that that seems to be a silly requirement, so I'd like to avoid

Silly or not, it keeps your code simpler, and simplicity just cannot be
overvalued.

> it.  (That's the "solution" that I currently have working with
> __getattr__.)

I'm confident that after you have been coding in Python for a while the
Javaisms will wither away. For now, if you feel that uppercase module-level
names are too big a leap I suggest that you add a __setattr__() method that
records any attempts to modify read-only attributes. That way you'll have a
way to learn whether that particular safety net was a useful investment or
just dead code.

Peter