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Groups > comp.lang.python > #37332
| Date | 2013-01-22 18:49 +0000 |
|---|---|
| From | MRAB <python@mrabarnett.plus.com> |
| Subject | Re: Using filepath method to identify an .html page |
| References | (8 earlier) <ec8f1a56-d0f7-46a6-a8a3-9425d3aabf8e@googlegroups.com> <mailman.796.1358868351.2939.python-list@python.org> <12a22c5b-88a9-4577-a642-abe1e56cce5e@googlegroups.com> <mailman.803.1358871083.2939.python-list@python.org> <8ad4a124-37a8-41fc-938d-9535b8affcbf@googlegroups.com> |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.823.1358880581.2939.python-list@python.org> (permalink) |
On 2013-01-22 18:26, Ferrous Cranus wrote:
> Τη Τρίτη, 22 Ιανουαρίου 2013 6:11:20 μ.μ. UTC+2, ο χρήστης Chris Angelico έγραψε:
>> On Wed, Jan 23, 2013 at 2:59 AM, Ferrous Cranus <nikos.gr33k@gmail.com> wrote:
>>
>> > I just need a way to CONVERT a string(absolute path) to a 4-digit unique number with INT!!! That's all i want!! But i cannot make it work :(
>>
>> Either you are deliberately trolling, or you have a major
>> comprehension problem. Please go back and read, carefully, all the
>> remarks you've been offered in this thread. Feel free to ask for
>> clarification of anything that doesn't make sense, but be sure to read
>> all of it. You are asking something that is fundamentally
>> impossible[1]. There simply are not enough numbers to go around.
>>
>> ChrisA
>>
>> [1] Well, impossible in decimal. If you work in base 4294967296, you
>>
>> could do what you want in four "digits".
>
> Fundamentally impossible?
>
Yes.
> Well....
>
> OK: How about this in Perl:
>
> $ cat testMD5.pl
> use strict;
>
> foreach my $url(qw@ /index.html /about/time.html @){
> hashit($url);
> }
>
> sub hashit {
> my $url=shift;
> my @ltrs=split(//,$url);
> my $hash = 0;
>
> foreach my $ltr(@ltrs){
> $hash = ( $hash + ord($ltr)) %10000;
> }
> printf "%s: %0.4d\n",$url,$hash
>
> }
>
>
> which yields:
> $ perl testMD5.pl
> /index.html: 1066
> /about/time.html: 1547
>
That shortens the int to 4 digits.
A hash isn't guaranteed to be unique. A hash is an attempt to make an
int which is highly sensitive to a change in the data so that a small
change in the data will result in a different int. If the change is big
enough it _could_ give the same int, but the hope is that it probably
won't. (Ideally, if the hash has 4 decimal digits, you'd hope that the
chance of different data giving the same hash would be about 1 in
10000.)
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Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 02:07 -0800
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 11:31 +0000
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 03:53 -0800
Re: Using filepath method to identify an .html page Chris Angelico <rosuav@gmail.com> - 2013-01-22 23:26 +1100
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 04:02 -0800
Re: Using filepath method to identify an .html page Lele Gaifax <lele@metapensiero.it> - 2013-01-22 13:22 +0100
Re: Using filepath method to identify an .html page Dave Angel <d@davea.name> - 2013-01-22 07:29 -0500
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 04:47 -0800
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 04:50 -0800
Re: Using filepath method to identify an .html page Chris Angelico <rosuav@gmail.com> - 2013-01-22 23:59 +1100
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 04:50 -0800
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 04:47 -0800
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 13:04 +0000
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 05:57 -0800
Re: Using filepath method to identify an .html page Chris Angelico <rosuav@gmail.com> - 2013-01-23 01:33 +1100
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 06:55 -0800
Re: Using filepath method to identify an .html page Dave Angel <d@davea.name> - 2013-01-22 10:05 -0500
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 07:21 -0800
Re: Using filepath method to identify an .html page Chris Angelico <rosuav@gmail.com> - 2013-01-23 02:27 +1100
Re: Using filepath method to identify an .html page Michael Torrie <torriem@gmail.com> - 2013-01-22 11:36 -0700
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 23:40 +0000
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 23:40 +0000
Re: Using filepath method to identify an .html page Michael Torrie <torriem@gmail.com> - 2013-01-22 17:07 -0700
Re: Using filepath method to identify an .html page MRAB <python@mrabarnett.plus.com> - 2013-01-23 00:40 +0000
Re: Using filepath method to identify an .html page rusi <rustompmody@gmail.com> - 2013-01-22 18:55 -0800
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-23 02:50 +0000
Re: Using filepath method to identify an .html page rusi <rustompmody@gmail.com> - 2013-01-22 19:04 -0800
Re: Using filepath method to identify an .html page Chris Angelico <rosuav@gmail.com> - 2013-01-23 15:44 +1100
Re: Using filepath method to identify an .html page Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-01-22 22:15 -0500
Re: Using filepath method to identify an .html page MRAB <python@mrabarnett.plus.com> - 2013-01-23 03:35 +0000
Re: Using filepath method to identify an .html page Michael Torrie <torriem@gmail.com> - 2013-01-22 22:10 -0700
Re: Using filepath method to identify an .html page Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-01-23 01:13 -0500
RE: Using filepath method to identify an .html page "Leonard, Arah" <Arah.Leonard@bruker-axs.com> - 2013-01-23 16:33 +0000
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-23 08:51 -0800
RE: Using filepath method to identify an .html page "Leonard, Arah" <Arah.Leonard@bruker-axs.com> - 2013-01-23 18:19 +0000
Re: Using filepath method to identify an .html page Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-01-23 18:36 +0000
Re: Using filepath method to identify an .html page Dave Angel <d@davea.name> - 2013-01-23 17:46 -0500
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-23 08:51 -0800
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 23:34 +0000
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 23:35 +0000
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 23:34 +0000
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 23:36 +0000
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 23:36 +0000
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 23:37 +0000
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 23:39 +0000
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 23:38 +0000
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 23:39 +0000
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 23:37 +0000
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 23:38 +0000
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 23:39 +0000
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 23:36 +0000
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 23:35 +0000
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 23:37 +0000
Re: Using filepath method to identify an .html page Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-01-22 16:44 -0500
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 07:21 -0800
Re: Using filepath method to identify an .html page Chris Angelico <rosuav@gmail.com> - 2013-01-23 02:07 +1100
Re: Using filepath method to identify an .html page Peter Otten <__peter__@web.de> - 2013-01-22 16:25 +0100
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 07:46 -0800
Re: Using filepath method to identify an .html page Dave Angel <d@davea.name> - 2013-01-22 11:11 -0500
RE: Using filepath method to identify an .html page "Leonard, Arah" <Arah.Leonard@bruker-axs.com> - 2013-01-22 16:23 +0000
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 10:13 -0800
Re: Using filepath method to identify an .html page Michael Torrie <torriem@gmail.com> - 2013-01-22 11:43 -0700
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 10:13 -0800
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 07:46 -0800
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 07:59 -0800
Re: Using filepath method to identify an .html page Chris Angelico <rosuav@gmail.com> - 2013-01-23 03:11 +1100
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 10:26 -0800
Re: Using filepath method to identify an .html page MRAB <python@mrabarnett.plus.com> - 2013-01-22 18:49 +0000
Re: Using filepath method to identify an .html page Michael Torrie <torriem@gmail.com> - 2013-01-22 11:49 -0700
Re: Using filepath method to identify an .html page Dave Angel <d@davea.name> - 2013-01-22 14:00 -0500
Re: Using filepath method to identify an .html page Peter Otten <__peter__@web.de> - 2013-01-22 20:16 +0100
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 23:25 -0800
Re: Using filepath method to identify an .html page Michael Torrie <torriem@gmail.com> - 2013-01-23 08:25 -0700
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-23 07:56 -0800
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-23 07:56 -0800
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 23:25 -0800
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 10:26 -0800
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 07:59 -0800
Re: Using filepath method to identify an .html page John Gordon <gordon@panix.com> - 2013-01-22 16:55 +0000
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 10:07 -0800
Re: Using filepath method to identify an .html page John Gordon <gordon@panix.com> - 2013-01-22 18:37 +0000
Re: Using filepath method to identify an .html page Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-01-22 17:01 -0500
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 23:23 +0000
Re: Using filepath method to identify an .html page rusi <rustompmody@gmail.com> - 2013-01-22 09:33 -0800
Re: Using filepath method to identify an .html page Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-01-22 17:54 +0000
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 10:23 -0800
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 22:45 +0000
Re: Using filepath method to identify an .html page Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-22 22:44 +0000
Re: Using filepath method to identify an .html page Mitya Sirenef <msirenef@lightbird.net> - 2013-01-22 19:23 -0500
Re: Using filepath method to identify an .html page Ferrous Cranus <nikos.gr33k@gmail.com> - 2013-01-22 06:55 -0800
Re: Using filepath method to identify an .html page Michael Torrie <torriem@gmail.com> - 2013-01-22 11:21 -0700
Re: Using filepath method to identify an .html page alex23 <wuwei23@gmail.com> - 2013-01-22 17:27 -0800
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