Generator expressions v/s list comprehensions

[Jeremy Bowers]

On Mon, 30 Aug 2004 01:23:16 -0700, Paul Rubin wrote:

>  These things exist in other languages and had been
> requested in Python for years before they got accepted.  And every
> time some little thing gets added changing the language, that creates
> a new mini-dialect that users have to remember for a while and then
> forget.  The result is "version fatigue"; one gets bleary trying to
> remember what's in the language this week.  Those features are in
> other languages for a reason, and there's been enough experience using
> them (in those languages) that their desirability for Python should
> never have seriously been in question.

Along with the other two poster's points, you have a whiff of an implied
argument that somehow, these amorphous "other languages" somehow *didn't*
go through "version fatigue", and are therefore somehow better. This is
false if you take it out of the realm of amorphous, implied claim and look
at it in the light of day. Show me a language that has never suffered from
these problems and anyone actually uses. If you can show me one, show me a
few more.

C changed. C++ changed. Fortran changed. COBOL changed. LISP has changed.
Python changed, Perl changed, Haskell changed, Javascript changed,
everything changed. None of those languages decided that the correct
solution is to simply throw everything in (even Ada, C++, and Perl, all of
which have that reputation, really didn't in the sense you're getting at
here). 

The claim that other languages have features, *therefore* we shouldn't
stop to think about whether they are good and they should all be added to
Python without debate boggles the mind when viewed head on. Pure
non-sequitor.

(BTW, note levels of debate are proportional to how many people bother to
debate, and nothing else. It is one reason a language can not
effectively grow to the community size of Python without strong leadership
and why I am glad that Python runs under a BDFL system. Most of the debate
you may see here in c.l.p. is really effectively irrelevant, and should be
mentally categorized as such; that debate does not constitute true design
involvement. Thus, pointing out "high levels of debate" in the newsgroup
doesn't convince me of much, since it really means little. To the extent
that it does sometimes matter, the amortized effect of any given message
is simply miniscule; the entire debate of a thousand messages may have no
effect whatsoever on Guido, or manifest itself as a single document of
moderate length that he may *still* reject.)