[Python-ideas] "value" ~ "data" ~ "object"

[Bruce Leban]

data = plural of datum

both words are commonly misused as to singular/plural usage.
"piece/unit/item of data" is a common substitution for "datum" by people who
don't know the word. [Likewise, "media" is the plural of "medium" but people
get that confused too.]

With numbers, a single number is a datum. More than one numbers are data.

You would never refer to "the value X" (where X is a python variable) but
you would refer to "the value 3" or "the value pi". Generally, in English
when people say "data" they're referring to the numbers in a more abstract
sense than 3 and pi.

I would say that roughly:

value : datum :: instance : object

But this is hardly precise. People frequently refer to A as an object when
we really mean it's an instance of the object [e.g., class] Alpha.

--- Bruce
http://www.vroospeak.com


2010/4/15 spir ☣ <denis.spir at gmail.com>

> On Thu, 15 Apr 2010 14:31:49 +0100
> Conrad Irwin <conrad.irwin at googlemail.com> wrote:
>
> >
> > On 04/15/2010 12:37 PM, spir ☣ wrote:
> > > Hello,
> > >
> > > I have been recently thinking at lexical distinctions around the notion
> of data. (--> eg for a starting point http://c2.com/cgi/wiki?WhatIsData)
> Not only but especially in Python. I ended up with the following questions:
> > > Can one state "in Python value=data=object"?
> > > Can one state "in Python speak value=data=object"?
> > >
> > > What useful distinctions are or may be done, for instance in
> documentation?
> > > What kind of difference in actual language semantics may such
> distinctions mirror?
> >
> > Uh.. you are trying to have a discussion about detailed semantics
> > without defining what you mean by any of your terminology.
>
> This is precisely the point: how to properly use given terms -- giving them
> semantic distinctions or not.
>
> > [...]
>
> > (and for the most part, objects with the same values have different data
> too).
>
> Right, this makes sense for me. And do you mean data are different as soon
> as located at different places in memory even if bit-per-bit equal? Or only
> that value holds a notion of interpretation (due to the type)?
>
> > [...]
>
> > It shouldn't
> > be necessary to make the distinction between an object and its value in
> > documentation (though it is (I presume) occasionally useful in actual
> > code to distinguish objects with the same datum, perhaps in cycle
> > detection).
>
> Thank you. Let us take the case of a simple assignment:
>   name = expression
> Once the expression is evaluated, what we get is commonly called a value,
> right? But in numerous places the result of data lookup is called object
> instead. While conceptually, for me, it's exactly the same thing.
>   x.a = 1
> results in an attribute 'a' with "value" 1, in x.
>   b = x.a
> looks up for the "object" denoted to by the attr name 'a' in x.
>
> (I'm not trying to annoy people, just to clarify common notions.)
>
> > Conrad
>
>
>
> ________________________________
>
> vit esse estrany ☣
>
> spir.wikidot.com
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