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Groups > comp.lang.python > #11679

Re: testing if a list contains a sublist

From Nobody <nobody@nowhere.com>
Subject Re: testing if a list contains a sublist
Date 2011-08-17 13:28 +0100
Message-Id <pan.2011.08.17.12.28.42.227000@nowhere.com>
Newsgroups comp.lang.python
References <mailman.27.1313450819.27778.python-list@python.org> <pan.2011.08.16.11.21.47.168000@nowhere.com> <mailman.65.1313504884.27778.python-list@python.org>
Organization Zen Internet

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On Tue, 16 Aug 2011 09:57:57 -0400, John Posner wrote:

> How about using Python's core support for "==" on list objects:

>     for i in range(alist_sz - slist_sz + 1):
>         if slist == alist[i:i+slist_sz]:
>             return True

This is bound to be asymptotically O(alist_sz * slist_sz), even if the
constant factor is reduced by use of ==. Boyer-Moore and regexps are
asymptotically O(alist_sz). However, the setup costs are much higher, so
you might need alist_sz to be very large before they win out.

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Thread

testing if a list contains a sublist Johannes <dajo.mail@web.de> - 2011-08-16 01:26 +0200
  Re: testing if a list contains a sublist Roy Smith <roy@panix.com> - 2011-08-15 20:53 -0400
    Re: testing if a list contains a sublist Laszlo Nagy <gandalf@shopzeus.com> - 2011-08-16 08:51 +0200
      Re: testing if a list contains a sublist alex23 <wuwei23@gmail.com> - 2011-08-16 00:19 -0700
      Re: testing if a list contains a sublist alex23 <wuwei23@gmail.com> - 2011-08-16 00:14 -0700
        Re: testing if a list contains a sublist Laszlo Nagy <gandalf@shopzeus.com> - 2011-08-16 10:00 +0200
        Re: testing if a list contains a sublist Johannes <dajo.mail@web.de> - 2011-08-16 17:26 +0200
      Re: testing if a list contains a sublist ChasBrown <cbrown@cbrownsystems.com> - 2011-08-16 00:24 -0700
    Re: testing if a list contains a sublist Alain Ketterlin <alain@dpt-info.u-strasbg.fr> - 2011-08-16 14:23 +0200
      Re: testing if a list contains a sublist Roy Smith <roy@panix.com> - 2011-08-16 08:53 -0400
      Re: testing if a list contains a sublist nn <pruebauno@latinmail.com> - 2011-08-16 07:53 -0700
        Re: testing if a list contains a sublist Laszlo Nagy <gandalf@shopzeus.com> - 2011-08-16 17:17 +0200
          Re: testing if a list contains a sublist Alain Ketterlin <alain@dpt-info.u-strasbg.fr> - 2011-08-16 17:39 +0200
        Re: testing if a list contains a sublist Neil Cerutti <neilc@norwich.edu> - 2011-08-16 17:45 +0000
  Re: testing if a list contains a sublist Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-08-16 12:12 +1000
    Re: testing if a list contains a sublist Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-08-16 18:19 +1000
  Re: testing if a list contains a sublist ChasBrown <cbrown@cbrownsystems.com> - 2011-08-15 23:14 -0700
  Re: testing if a list contains a sublist ChasBrown <cbrown@cbrownsystems.com> - 2011-08-15 23:13 -0700
  Re: testing if a list contains a sublist ChasBrown <cbrown@cbrownsystems.com> - 2011-08-15 23:14 -0700
    Re: testing if a list contains a sublist Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-08-16 18:37 +1000
      Re: testing if a list contains a sublist ChasBrown <cbrown@cbrownsystems.com> - 2011-08-16 21:13 -0700
  Re: testing if a list contains a sublist Nobody <nobody@nowhere.com> - 2011-08-16 12:21 +0100
    Re: testing if a list contains a sublist John Posner <jjposner@codicesoftware.com> - 2011-08-16 09:57 -0400
    Re: testing if a list contains a sublist John Posner <jjposner@optimum.net> - 2011-08-16 09:57 -0400
      Re: testing if a list contains a sublist Nobody <nobody@nowhere.com> - 2011-08-17 13:28 +0100
  Re: testing if a list contains a sublist Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-08-20 12:10 +1000

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