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Groups > comp.lang.python > #5639

Re: English Idiom in Unix: Directory Recursively

Date 2011-05-17 21:16 -0400
From "Steven W. Orr" <steveo@syslang.net>
Organization SysLang, Inc.
Subject Re: English Idiom in Unix: Directory Recursively
References <c159267e-22f9-4821-a70d-2f111cc35de4@f31g2000pri.googlegroups.com>
Newsgroups comp.lang.python
Message-ID <mailman.1733.1305681447.9059.python-list@python.org> (permalink)

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On 5/17/2011 6:26 PM, Xah Lee wrote:
> might be of interest.
>
> 〈English Idiom in Unix: Directory Recursively〉
> http://xahlee.org/comp/idiom_directory_recursively.html

The answer is from compute science 101. From any standard data structures 
course, you learn the algorithm for how to walk a tree. To make it simple, the 
example is to use a binary tree which means that any non-leaf node of a tree may 
only have two child nodes, which are designated as Left and Right. There are 
only three things that are possible: Visit, Go Left, or Go Right. This means 
that a tree traversal program can only be written three ways:
A PreOrder Traversal will Visit, Go Left, Go Right.
An InOrder Traversal will Go Left, Visit, Go Right.
A PostOrder Traversal will Go Left, Go Right, Visit.

So, the Visit function is the function that does whatever you want to have 
happen at that node. Selection of whether you want to do things like copy, print 
or delete are designated by what kind of traversal you perform. And, since the 
Traversal function calls itself, it is, by definition, recursive.

QED.

-- 
Time flies like the wind. Fruit flies like a banana. Stranger things have  .0.
happened but none stranger than this. Does your driver's license say Organ ..0
Donor?Black holes are where God divided by zero. Listen to me! We are all- 000
individuals! What if this weren't a hypothetical question?
steveo at syslang.net

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English Idiom in Unix: Directory Recursively Xah Lee <xahlee@gmail.com> - 2011-05-17 15:26 -0700
  Re: English Idiom in Unix: Directory Recursively Ian Kelly <ian.g.kelly@gmail.com> - 2011-05-17 17:20 -0600
    Re: English Idiom in Unix: Directory Recursively "Martin P. Hellwig" <martin.hellwig@gmail.com> - 2011-05-18 22:22 +0000
  Re: English Idiom in Unix: Directory Recursively Chris Angelico <rosuav@gmail.com> - 2011-05-18 09:42 +1000
  Re: English Idiom in Unix: Directory Recursively "Steven W. Orr" <steveo@syslang.net> - 2011-05-17 21:16 -0400
  Re: English Idiom in Unix: Directory Recursively Roland Hutchinson <my.spamtrap@verizon.net> - 2011-05-18 04:51 +0000
    Re: English Idiom in Unix: Directory Recursively "Pascal J. Bourguignon" <pjb@informatimago.com> - 2011-05-18 07:19 +0200
      Re: English Idiom in Unix: Directory Recursively tar@sevak.isi.edu (Thomas A. Russ) - 2011-05-17 23:42 -0700
        Re: English Idiom in Unix: Directory Recursively Hans Georg Schaathun <hg@schaathun.net> - 2011-05-18 09:26 +0100
          Re: English Idiom in Unix: Directory Recursively tar@sevak.isi.edu (Thomas A. Russ) - 2011-05-18 09:16 -0700
            Re: English Idiom in Unix: Directory Recursively Hans Georg Schaathun <hg@schaathun.net> - 2011-05-18 19:11 +0100
              Re: English Idiom in Unix: Directory Recursively Raymond Wiker <raw@RAWMBP-2.local> - 2011-05-18 20:20 +0200
                Re: English Idiom in Unix: Directory Recursively Hans Georg Schaathun <hg@schaathun.net> - 2011-05-18 19:39 +0100
                Re: English Idiom in Unix: Directory Recursively Raymond Wiker <raw@RAWMBP-2.local> - 2011-05-18 21:09 +0200
                Re: English Idiom in Unix: Directory Recursively Hans Georg Schaathun <hg@schaathun.net> - 2011-05-18 21:02 +0100
                Re: English Idiom in Unix: Directory Recursively Raymond Wiker <raw@RAWMBP-2.local> - 2011-05-18 22:40 +0200
                Re: English Idiom in Unix: Directory Recursively Hans Georg Schaathun <hg@schaathun.net> - 2011-05-19 05:56 +0100
                Re: English Idiom in Unix: Directory Recursively tar@sevak.isi.edu (Thomas A. Russ) - 2011-05-19 16:14 -0700
                Re: English Idiom in Unix: Directory Recursively Chris Angelico <rosuav@gmail.com> - 2011-05-19 04:41 +1000
            Re: English Idiom in Unix: Directory Recursively Chris Angelico <rosuav@gmail.com> - 2011-05-19 04:12 +1000
            Re: English Idiom in Unix: Directory Recursively "Pascal J. Bourguignon" <pjb@informatimago.com> - 2011-05-18 20:57 +0200
              Re: English Idiom in Unix: Directory Recursively tar@sevak.isi.edu (Thomas A. Russ) - 2011-05-19 16:17 -0700
                Re: English Idiom in Unix: Directory Recursively "Pascal J. Bourguignon" <pjb@informatimago.com> - 2011-05-20 02:38 +0200
                Re: English Idiom in Unix: Directory Recursively Antti J Ylikoski <antti.ylikoski@tkk.fi> - 2011-05-20 12:00 +0300
        Re: English Idiom in Unix: Directory Recursively Peter Moylan <invalid@peter.pmoylan.org.invalid> - 2011-05-18 22:09 +1000
          Re: English Idiom in Unix: Directory Recursively rusi <rustompmody@gmail.com> - 2011-05-18 06:14 -0700
            Re: English Idiom in Unix: Directory Recursively Peter Moylan <invalid@peter.pmoylan.org.invalid> - 2011-05-19 11:06 +1000
              Re: English Idiom in Unix: Directory Recursively Jonathan de Boyne Pollard <J.deBoynePollard-newsgroups@NTLWorld.COM> - 2011-05-21 09:32 +0100
                Re: English Idiom in Unix: Directory Recursively Lars Enderin <lars.enderin@telia.com> - 2011-05-21 11:52 +0200
                Re: English Idiom in Unix: Directory Recursively Lars Enderin <lars.enderin@telia.com> - 2011-05-21 11:54 +0200
                Re: English Idiom in Unix: Directory Recursively Lars Enderin <lars.enderin@telia.com> - 2011-05-21 11:56 +0200
              Re: English Idiom in Unix: Directory Recursively Grant Edwards <invalid@invalid.invalid> - 2011-05-21 15:34 +0000
      Re: English Idiom in Unix: Directory Recursively Roland Hutchinson <my.spamtrap@verizon.net> - 2011-05-20 06:50 +0000
    Re: English Idiom in Unix: Directory Recursively rusi <rustompmody@gmail.com> - 2011-05-17 23:06 -0700
      Re: English Idiom in Unix: Directory Recursively Harrison Hill <harrishill@gmx.com> - 2011-05-17 23:50 -0700
        Re: English Idiom in Unix: Directory Recursively rusi <rustompmody@gmail.com> - 2011-05-18 00:16 -0700
        Re: English Idiom in Unix: Directory Recursively Peter Moylan <invalid@peter.pmoylan.org.invalid> - 2011-05-18 22:19 +1000
          Re: English Idiom in Unix: Directory Recursively rantingrick <rantingrick@gmail.com> - 2011-05-29 13:16 -0700
            Re: English Idiom in Unix: Directory Recursively Peter Moylan <invalid@peter.pmoylan.org.invalid> - 2011-05-30 22:58 +1000
        Re: English Idiom in Unix: Directory Recursively see@sig.for.address (Victor Eijkhout) - 2011-05-18 12:59 -0500
          Re: English Idiom in Unix: Directory Recursively Roland Hutchinson <my.spamtrap@verizon.net> - 2011-05-20 06:54 +0000
            Re: English Idiom in Unix: Directory Recursively Chris Angelico <rosuav@gmail.com> - 2011-05-20 17:10 +1000
          Re: English Idiom in Unix: Directory Recursively rantingrick <rantingrick@gmail.com> - 2011-05-29 13:28 -0700
            Re: English Idiom in Unix: Directory Recursively Peter Moylan <invalid@peter.pmoylan.org.invalid> - 2011-05-30 23:02 +1000
          Re: English Idiom in Unix: Directory Recursively rantingrick <rantingrick@gmail.com> - 2011-05-29 13:28 -0700
        Re: English Idiom in Unix: Directory Recursively Glenn Knickerbocker <NotR@bestweb.net> - 2011-05-18 16:54 -0400
      Re: English Idiom in Unix: Directory Recursively Ian Kelly <ian.g.kelly@gmail.com> - 2011-05-18 00:58 -0600
        Re: English Idiom in Unix: Directory Recursively rusi <rustompmody@gmail.com> - 2011-05-18 00:10 -0700
          Re: English Idiom in Unix: Directory Recursively Ian Kelly <ian.g.kelly@gmail.com> - 2011-05-18 08:32 -0600
            Re: English Idiom in Unix: Directory Recursively rusi <rustompmody@gmail.com> - 2011-05-18 08:15 -0700
              Re: English Idiom in Unix: Directory Recursively Ian Kelly <ian.g.kelly@gmail.com> - 2011-05-18 09:43 -0600
  Re: English Idiom in Unix: Directory Recursively Hans Georg Schaathun <hg@schaathun.net> - 2011-05-18 09:12 +0100
    Re: English Idiom in Unix: Directory Recursively Espen Vestre <espen@vestre.net> - 2011-05-18 10:20 +0200
    Re: English Idiom in Unix: Directory Recursively Rikishi42 <skunkworks@rikishi42.net> - 2011-05-19 23:21 +0200
      Re: English Idiom in Unix: Directory Recursively Hans Georg Schaathun <hg@schaathun.net> - 2011-05-20 05:28 +0100
        Re: English Idiom in Unix: Directory Recursively Rikishi42 <skunkworks@rikishi42.net> - 2011-05-23 20:48 +0200
      Re: English Idiom in Unix: Directory Recursively rusi <rustompmody@gmail.com> - 2011-05-19 22:13 -0700
        Re: English Idiom in Unix: Directory Recursively Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-20 06:55 +0000
          Re: English Idiom in Unix: Directory Recursively Hans Georg Schaathun <hg@schaathun.net> - 2011-05-20 09:48 +0100
            Re: English Idiom in Unix: Directory Recursively rusi <rustompmody@gmail.com> - 2011-05-20 10:21 -0700
          Re: English Idiom in Unix: Directory Recursively Rikishi42 <skunkworks@rikishi42.net> - 2011-05-23 20:56 +0200
            Re: English Idiom in Unix: Directory Recursively Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-24 00:18 +0000
              Re: English Idiom in Unix: Directory Recursively Rikishi42 <skunkworks@rikishi42.net> - 2011-05-25 00:06 +0200
                Re: English Idiom in Unix: Directory Recursively Chris Angelico <rosuav@gmail.com> - 2011-05-25 10:40 +1000
                Re: English Idiom in Unix: Directory Recursively rantingrick <rantingrick@gmail.com> - 2011-05-29 14:18 -0700
                Re: English Idiom in Unix: Directory Recursively rantingrick <rantingrick@gmail.com> - 2011-05-29 14:19 -0700
                Re: English Idiom in Unix: Directory Recursively Xah Lee <xahlee@gmail.com> - 2011-05-24 23:05 -0700
                Re: English Idiom in Unix: Directory Recursively Thorsten Kampe <thorsten@thorstenkampe.de> - 2011-05-25 09:26 +0200
                Re: English Idiom in Unix: Directory Recursively Xah Lee <xahlee@gmail.com> - 2011-05-25 00:51 -0700
                Re: English Idiom in Unix: Directory Recursively Chris Angelico <rosuav@gmail.com> - 2011-05-25 17:59 +1000
                Re: English Idiom in Unix: Directory Recursively Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-25 21:59 +0000
                Re: English Idiom in Unix: Directory Recursively Thorsten Kampe <thorsten@thorstenkampe.de> - 2011-05-26 10:48 +0200
                Re: English Idiom in Unix: Directory Recursively Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-26 10:06 +0000
                Re: English Idiom in Unix: Directory Recursively Thorsten Kampe <thorsten@thorstenkampe.de> - 2011-05-26 12:46 +0200
                Re: English Idiom in Unix: Directory Recursively harrismh777 <harrismh777@charter.net> - 2011-05-27 09:31 -0500
                Re: English Idiom in Unix: Directory Recursively Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-25 22:58 +0000
                Re: English Idiom in Unix: Directory Recursively Chris Angelico <rosuav@gmail.com> - 2011-05-26 14:00 +1000
                Re: English Idiom in Unix: Directory Recursively Thorsten Kampe <thorsten@thorstenkampe.de> - 2011-05-26 10:59 +0200
                Re: English Idiom in Unix: Directory Recursively "Charles" <C.Sanders@DeleteThis.Bom.GOV.AU> - 2011-05-26 20:58 +1000
                Re: English Idiom in Unix: Directory Recursively Chris Angelico <rosuav@gmail.com> - 2011-05-26 21:12 +1000
                Re: English Idiom in Unix: Directory Recursively rantingrick <rantingrick@gmail.com> - 2011-05-29 14:38 -0700
                Re: English Idiom in Unix: Directory Recursively Chris Angelico <rosuav@gmail.com> - 2011-05-30 07:46 +1000
                Re: English Idiom in Unix: Directory Recursively rantingrick <rantingrick@gmail.com> - 2011-05-29 15:54 -0700
                Re: English Idiom in Unix: Directory Recursively rantingrick <rantingrick@gmail.com> - 2011-05-29 14:38 -0700
                Re: English Idiom in Unix: Directory Recursively Thorsten Kampe <thorsten@thorstenkampe.de> - 2011-05-26 13:20 +0200
                Re: English Idiom in Unix: Directory Recursively Chris Angelico <rosuav@gmail.com> - 2011-05-26 21:28 +1000
                Re: English Idiom in Unix: Directory Recursively Xah Lee <xahlee@gmail.com> - 2011-05-26 14:51 -0700
                Re: English Idiom in Unix: Directory Recursively Rikishi42 <skunkworks@rikishi42.net> - 2011-05-28 21:36 +0200
                Re: English Idiom in Unix: Directory Recursively Chris Angelico <rosuav@gmail.com> - 2011-05-29 05:58 +1000
                Re: English Idiom in Unix: Directory Recursively Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-29 00:49 +0000
                Re: English Idiom in Unix: Directory Recursively Rikishi42 <skunkworks@rikishi42.net> - 2011-05-30 23:04 +0200
                Re: English Idiom in Unix: Directory Recursively Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-30 23:17 +0000
                Re: English Idiom in Unix: Directory Recursively Chris Angelico <rosuav@gmail.com> - 2011-05-29 07:28 +1000
                Re: English Idiom in Unix: Directory Recursively Rikishi42 <skunkworks@rikishi42.net> - 2011-05-30 23:10 +0200
                Re: English Idiom in Unix: Directory Recursively rantingrick <rantingrick@gmail.com> - 2011-05-29 13:58 -0700
                Re: English Idiom in Unix: Directory Recursively Chris Angelico <rosuav@gmail.com> - 2011-05-30 07:27 +1000
          Re: English Idiom in Unix: Directory Recursively rantingrick <rantingrick@gmail.com> - 2011-05-29 13:39 -0700
  Re: English Idiom in Unix: Directory Recursively Mike Barnes <mikebarnes@bluebottle.com> - 2011-05-18 10:25 +0100
    Re: English Idiom in Unix: Directory Recursively Xah Lee <xahlee@gmail.com> - 2011-05-18 13:00 -0700
      Re: English Idiom in Unix: Directory Recursively Hans Georg Schaathun <hg@schaathun.net> - 2011-05-18 21:19 +0100
        Re: English Idiom in Unix: Directory Recursively Lanarcam <lanarcam1@yahoo.fr> - 2011-05-18 22:33 +0200
      Re: English Idiom in Unix: Directory Recursively Mike Barnes <mikebarnes@bluebottle.com> - 2011-05-18 22:00 +0100
      Re: English Idiom in Unix: Directory Recursively Jonathan de Boyne Pollard <J.deBoynePollard-newsgroups@NTLWorld.COM> - 2011-05-20 08:10 +0100
        Re: English Idiom in Unix: Directory Recursively Xah Lee <xahlee@gmail.com> - 2011-05-22 13:22 -0700
          Re: English Idiom in Unix: Directory Recursively Chris Angelico <rosuav@gmail.com> - 2011-05-23 08:46 +1000
            Re: English Idiom in Unix: Directory Recursively Xah Lee <xahlee@gmail.com> - 2011-05-22 16:17 -0700
              Re: English Idiom in Unix: Directory Recursively Chris Angelico <rosuav@gmail.com> - 2011-05-23 09:32 +1000
                Re: English Idiom in Unix: Directory Recursively Xah Lee <xahlee@gmail.com> - 2011-05-23 21:20 -0700
                Re: English Idiom in Unix: Directory Recursively Chris Angelico <rosuav@gmail.com> - 2011-05-24 14:28 +1000
                Re: English Idiom in Unix: Directory Recursively Xah Lee <xahlee@gmail.com> - 2011-05-24 10:40 -0700
                Re: English Idiom in Unix: Directory Recursively Chris Angelico <rosuav@gmail.com> - 2011-05-25 08:14 +1000
                Re: English Idiom in Unix: Directory Recursively Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-25 10:15 +0000
      Re: English Idiom in Unix: Directory Recursively rantingrick <rantingrick@gmail.com> - 2011-05-29 13:32 -0700
    Re: English Idiom in Unix: Directory Recursively Jonathan de Boyne Pollard <J.deBoynePollard-newsgroups@NTLWorld.COM> - 2011-05-20 08:07 +0100
  Re: English Idiom in Unix: Directory Recursively John Nagle <nagle@animats.com> - 2011-05-18 13:07 -0700
  Re: English Idiom in Unix: Directory Recursively Jonathan de Boyne Pollard <J.deBoynePollard-newsgroups@NTLWorld.COM> - 2011-05-20 08:00 +0100
    Re: English Idiom in Unix: Directory Recursively David Schwartz <davids@webmaster.com> - 2011-05-27 22:56 -0700

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