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Date: Sat, 28 Jun 2014 23:50:26 +1000
Subject: Re: print statements and profiling a function slowed performance
From: Chris Angelico <rosuav@gmail.com>
Cc: "python-list@python.org" <python-list@python.org>
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Xref: csiph.com comp.lang.python:73705

On Sat, Jun 28, 2014 at 11:41 PM, Dennis Lee Bieber
<wlfraed@ix.netcom.com> wrote:
> On Fri, 27 Jun 2014 12:06:54 +1000, Chris Angelico <rosuav@gmail.com>
> declaimed the following:
>
>>
>>If x is, say, range(1000000), a simple "for foo in x: pass" will
>>complete fairly quickly (maybe 100ms on my computer), while the
>>progress-indicated loop will take much longer (about 30 seconds when I
>>tried it). Obviously you'll be doing more work than just "pass", but
>
>         I take it those are subjective feelings of time...

No, they were measured; but the exact difference will depend on Python
version, console, OS, etc, etc, etc, etc, etc, which is why I said
"maybe 100ms" - on one run it was about that (rounded aggressively to
make for convenient figures), but if I ran the test again, it might
come out at 50ms or 200ms. For what it's worth, I did the test on
Python 3.5(ish) on Linux; since you tested it on Python 2, a closer
comparison would be to use xrange rather than range, to avoid the RAM
overhead.

ChrisA