Speed-up for loops
Aahz
aahz at pythoncraft.com
Tue Sep 7 13:39:58 EDT 2010
In article <roy-0EC6F2.08091107092010 at news.panix.com>,
Roy Smith <roy at panix.com> wrote:
>
>Imagine that you're looking at some code which was written years ago, by
>people who are no longer around to answer questions. In one place, you
>see:
>
>for i in range(n):
> blah
>
>and in another, you see:
>
>for j in xrange(n):
> blah
>
>If you are truly a Python expert, you'll say to yourself, "range and
>xrange are synonyms", and move on to other things. If, however, you're
>not really an expert, you'll look at this and say, "Hmmm, in one place
>they used range(), and in another they used xrange(). Clearly, there's
>some reason for the difference, I need to figure out what it is, because
>that's probably key to my understanding why this code isn't working".
>So, you spend the next two hours pouring over reference manuals trying
>to understand the subtle difference, until your friend comes over and
>says, "You dolt, you just wasted half the afternoon. They're the same
>thing. Move on, this is not the bug you're looking for".
...and if you're a Python guru, you might spend a little bit of time
trying to figure out if the range() is causing the problem due to
allocating a large chunk of memory....
--
Aahz (aahz at pythoncraft.com) <*> http://www.pythoncraft.com/
"...if I were on life-support, I'd rather have it run by a Gameboy than a
Windows box." --Cliff Wells
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