can't add variables to instances of built-in classes

[Steven D'Aprano]

On Thu, 21 Jul 2016 08:11 am, Lawrence D’Oliveiro wrote:

> On Wednesday, July 20, 2016 at 9:16:30 PM UTC+12, Peter Otten wrote:
>>
>> Lawrence D’Oliveiro wrote:
>> 
>>> On Wednesday, July 20, 2016 at 7:26:36 PM UTC+12, Peter Otten wrote:
>>> 
>>>> pylint can detect candidates for accidental attribute creation:
>>> 
>>> And __slots__ will prevent them outright.
>> 
>> And attributes added intentionally.
> 
> You mean, being able to dynamically add new attributes to an object?
> 
> Probably not a good idea to mix that with read/write properties...

Why not?


If you're going to make a comment, would you please include some actual
significant information in your post? Dropping obtuse hints and incomplete
answers are not useful, and they give the strong impression that you are
only replying in order to gain a smug sense of superiority rather than to
disseminate knowledge and understanding.

Remember that other people cannot know the thought in your mind, they can
only judge by the actual words you have written, and if those words
standing alone do not explain your thinking, then people will:

(1) fail to understand the information you are trying to pass on;

(2) imagine that you are intentionally trying to be difficult; and

(3) characterise you as an insufferable, pretentious wanker who thinks that
giving mysterious, unintelligible responses makes him out to be ever-so
smarter than everyone else.


Poor quality answer:

"Probably not a good idea to mix that with read/write properties..."

Better:

"Probably not a good idea to mix that with read/write properties, for the
following reasons: [succinct explanation of the reasons why one should
avoid mixing ordinary attributes and properties]. Here's a longer
discussion [link to URL]."





-- 
Steven
“Cheer up,” they said, “things could be worse.” So I cheered up, and sure
enough, things got worse.