data = plural of datum<div><br></div><div>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.]</div>
<div><br></div><div>With numbers, a single number is a datum. More than one numbers are data.</div><div><br></div><div><div>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.</div>
</div><div><br></div><div><div>I would say that roughly:</div><div><br></div><div>value : datum :: instance : object<br clear="all"></div><div><br></div><div><div>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.</div>
<div><br></div></div></div><div>--- Bruce<br><a href="http://www.vroospeak.com">http://www.vroospeak.com</a><br>
<br><br><div class="gmail_quote">2010/4/15 spir ☣ <span dir="ltr"><<a href="mailto:denis.spir@gmail.com">denis.spir@gmail.com</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div class="im">On Thu, 15 Apr 2010 14:31:49 +0100<br>
Conrad Irwin <<a href="mailto:conrad.irwin@googlemail.com">conrad.irwin@googlemail.com</a>> wrote:<br>
<br>
><br>
> On 04/15/2010 12:37 PM, spir ☣ wrote:<br>
> > Hello,<br>
> ><br>
> > I have been recently thinking at lexical distinctions around the notion of data. (--> eg for a starting point <a href="http://c2.com/cgi/wiki?WhatIsData" target="_blank">http://c2.com/cgi/wiki?WhatIsData</a>) Not only but especially in Python. I ended up with the following questions:<br>
> > Can one state "in Python value=data=object"?<br>
> > Can one state "in Python speak value=data=object"?<br>
> ><br>
> > What useful distinctions are or may be done, for instance in documentation?<br>
> > What kind of difference in actual language semantics may such distinctions mirror?<br>
><br>
> Uh.. you are trying to have a discussion about detailed semantics<br>
> without defining what you mean by any of your terminology.<br>
<br>
</div>This is precisely the point: how to properly use given terms -- giving them semantic distinctions or not.<br>
<br>
> [...]<br>
<div class="im"><br>
> (and for the most part, objects with the same values have different data too).<br>
<br>
</div>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)?<br>
<br>
> [...]<br>
<div class="im"><br>
> It shouldn't<br>
> be necessary to make the distinction between an object and its value in<br>
> documentation (though it is (I presume) occasionally useful in actual<br>
> code to distinguish objects with the same datum, perhaps in cycle<br>
> detection).<br>
<br>
</div>Thank you. Let us take the case of a simple assignment:<br>
name = expression<br>
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.<br>
x.a = 1<br>
results in an attribute 'a' with "value" 1, in x.<br>
b = x.a<br>
looks up for the "object" denoted to by the attr name 'a' in x.<br>
<br>
(I'm not trying to annoy people, just to clarify common notions.)<br>
<br>
> Conrad<br>
<div class="im"><br>
<br>
<br>
________________________________<br>
<br>
vit esse estrany ☣<br>
<br>
<a href="http://spir.wikidot.com" target="_blank">spir.wikidot.com</a><br>
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</div></div></blockquote></div><br></div>