function v. method

[Bruno Desthuilliers]

Antoon Pardon wrote:
> On 2006-07-21, fuzzylollipop <jarrod.roberson at gmail.com> wrote:
> 
>>Antoon Pardon wrote:
>>
>>
>>>Suppose I am writing my own module, I use an underscore, to
>>>mark variables which are an implementation detail for my
>>>module.
>>>
>>>Now I need to import an other module in my module and need access
>>>to an implementation variable from that module. So now I have
>>>variables with an underscore which have two different meanings:
>>
>>you don't understand what "implementation detail" means, it means it is
>>NOT part of the public API and no client code should ever use it.
>>
>>If you reference _vara in your code and it is in someone elses module
>>you don't understand YOU ARE NOT SUPPOSED TO DO THAT!
> 
> 
> Why do you assume that in my example the other module is
> not understood?

He doesn't, but it's clear that *you* didn't understand what
fuzzylollipop meant !-)

Hint : add a comma at the right place so parsing is unambigous:
"""
If you reference _vara in your code and it is in someone elses module,
you don't understand YOU ARE NOT SUPPOSED TO DO THAT!
"""


> 
>>>  1) This is an implemantation detail of this module, It is the
>>>     users of my module who have to be extra carefull using it.
>>
>>Users of your module should NEVER KNOW any of the _ or __ stuff exists
>>to begin with.
>>
>>
>>>  2) This is an implemantation detail of the other module,
>>>     I should be extra carefull using it.
>>
>>You should NEVER use it.
> 
> 
> Well that may be your view, but AFAICS it is not the view of
> the python community. Because each time some mechanism is
> proposed for real private variable, people oppose it, they
> want people to have access to what are supposed to be
> private variables.

I'd express it in a somewhat different way: the view of the Python
community is that language-inforced access restrictions are useless and
annoying, IOW an unnecessary pain. Which doesn't imply that messing with
implementation of other modules is actually *encouraged*. Having the
possibility to easily do so is quite handy when that's the only/less
worse solution, but is not a recommended approach in general.

-- 
bruno desthuilliers
python -c "print '@'.join(['.'.join([w[::-1] for w in p.split('.')]) for
p in 'onurb at xiludom.gro'.split('@')])"