Re: how to get the ordinal number in list

Newsgroups	comp.lang.python
Date	2014-08-08 20:48 -0700
References	<53E658CD.5020904@gmail.com> <CACwCsY7icE7X2upr0auNhe37xh5HdC09Ad4yaetqpo+fcoBRYg@mail.gmail.com> <mailman.12780.1407551775.18130.python-list@python.org> <53e59035$0$29998$c3e8da3$5496439d@news.astraweb.com>
Message-ID	<338e8fb0-c9ec-462a-b560-1c1ff77de17e@googlegroups.com> (permalink)
Subject	Re: how to get the ordinal number in list
From	Rustom Mody <rustompmody@gmail.com>

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On Saturday, August 9, 2014 8:36:28 AM UTC+5:30, Steven D'Aprano wrote:
> luofeiyu wrote:

> >  >>> x=["x1","x3","x7","x5","x3"]
> >  >>> x.index("x3")
> > 1
> > if i want the result of 1 and 4 ?

> def index_all(source, target):
>     results = []
>     for i, obj in enumerate(source):
>         if obj == target:
>             results.append(i)
>     return results

> index_all(x, "x3")
> => returns [1, 3]

Heh!
And the OP asked for a simplification!

>>> def index_all(lst, val): return (i for i,v in enumerate(lst) if v == val)
... 
>>> index_all("abcdeaga", "a")
<generator object <genexpr> at 0x7f21884797d0>
>>> list(index_all("abcdeaga", "a"))
[0, 5, 7]

[To the OP]
Yeah I am in the minority at least out here in considering
comprehensions simpler than loops. Take your pick

Thread

Re: how to get the ordinal number in list luofeiyu <elearn2014@gmail.com> - 2014-08-09 10:35 -0700
  Re: how to get the ordinal number in list Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-08-09 13:06 +1000
    Re: how to get the ordinal number in list Rustom Mody <rustompmody@gmail.com> - 2014-08-08 20:48 -0700
      Re: how to get the ordinal number in list Roy Smith <roy@panix.com> - 2014-08-09 11:34 -0400
        Re: how to get the ordinal number in list Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-08-10 09:43 +1000
        Re: how to get the ordinal number in list Rustom Mody <rustompmody@gmail.com> - 2014-08-10 09:28 -0700
          Re: how to get the ordinal number in list Roy Smith <roy@panix.com> - 2014-08-10 13:10 -0400
            Re: how to get the ordinal number in list Rustom Mody <rustompmody@gmail.com> - 2014-08-10 10:34 -0700
              Re: how to get the ordinal number in list Roy Smith <roy@panix.com> - 2014-08-10 14:14 -0400
                Re: how to get the ordinal number in list Rustom Mody <rustompmody@gmail.com> - 2014-08-10 11:26 -0700
                Re: how to get the ordinal number in list Chris Angelico <rosuav@gmail.com> - 2014-08-11 05:03 +1000
                Re: how to get the ordinal number in list Marko Rauhamaa <marko@pacujo.net> - 2014-08-10 22:14 +0300
                Re: how to get the ordinal number in list Chris Angelico <rosuav@gmail.com> - 2014-08-11 05:20 +1000
                Re: how to get the ordinal number in list Rustom Mody <rustompmody@gmail.com> - 2014-08-10 22:23 -0700
                Re: how to get the ordinal number in list Chris Angelico <rosuav@gmail.com> - 2014-08-11 15:46 +1000
                Re: how to get the ordinal number in list Rustom Mody <rustompmody@gmail.com> - 2014-08-10 23:22 -0700
                Re: how to get the ordinal number in list Steven D'Aprano <steve@pearwood.info> - 2014-08-11 08:55 +0000
                Re: how to get the ordinal number in list Chris Angelico <rosuav@gmail.com> - 2014-08-11 19:15 +1000
                Re: how to get the ordinal number in list Marko Rauhamaa <marko@pacujo.net> - 2014-08-11 12:35 +0300
                Re: how to get the ordinal number in list Chris Angelico <rosuav@gmail.com> - 2014-08-11 19:51 +1000
                Re: how to get the ordinal number in list Marko Rauhamaa <marko@pacujo.net> - 2014-08-11 13:46 +0300
                Re: how to get the ordinal number in list Chris Angelico <rosuav@gmail.com> - 2014-08-11 21:06 +1000
                Re: how to get the ordinal number in list Steven D'Aprano <steve@pearwood.info> - 2014-08-11 09:44 +0000
                Re: how to get the ordinal number in list Chris Angelico <rosuav@gmail.com> - 2014-08-11 19:53 +1000
                Re: how to get the ordinal number in list Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-08-11 21:30 +1000
                Re: how to get the ordinal number in list Chris Angelico <rosuav@gmail.com> - 2014-08-11 20:07 +1000
                Re: how to get the ordinal number in list Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-08-13 10:47 +1000
                Re: how to get the ordinal number in list Chris Angelico <rosuav@gmail.com> - 2014-08-13 11:31 +1000
                Re: how to get the ordinal number in list Roy Smith <roy@panix.com> - 2014-08-12 21:45 -0400
                Re: how to get the ordinal number in list Chris Angelico <rosuav@gmail.com> - 2014-08-13 12:06 +1000
                Re: how to get the ordinal number in list Roy Smith <roy@panix.com> - 2014-08-11 07:55 -0400
                Re: how to get the ordinal number in list Tim Chase <python.list@tim.thechases.com> - 2014-08-11 07:30 -0500
                Re: how to get the ordinal number in list Marko Rauhamaa <marko@pacujo.net> - 2014-08-11 15:41 +0300
                Re: how to get the ordinal number in list Chris Angelico <rosuav@gmail.com> - 2014-08-11 22:53 +1000
                Re: how to get the ordinal number in list Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-08-11 14:57 +0100
                Re: how to get the ordinal number in list Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-08-10 21:32 +0100
                Re: how to get the ordinal number in list Roy Smith <roy@panix.com> - 2014-08-10 18:01 -0400
                Re: how to get the ordinal number in list Chris Angelico <rosuav@gmail.com> - 2014-08-11 08:43 +1000
                Re: how to get the ordinal number in list Rustom Mody <rustompmody@gmail.com> - 2014-08-10 20:35 -0700
                Re: how to get the ordinal number in list Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-08-11 12:04 +1000
                Re: how to get the ordinal number in list Robert Kern <robert.kern@gmail.com> - 2014-08-11 12:56 +0100
                Re: how to get the ordinal number in list Rustom Mody <rustompmody@gmail.com> - 2014-08-11 05:11 -0700
                Re: how to get the ordinal number in list Chris Angelico <rosuav@gmail.com> - 2014-08-11 22:45 +1000
                Re: how to get the ordinal number in list Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-08-11 15:01 +0100
                Re: how to get the ordinal number in list alister <alister.nospam.ware@ntlworld.com> - 2014-08-11 12:30 +0000
                Re: how to get the ordinal number in list Marko Rauhamaa <marko@pacujo.net> - 2014-08-11 15:41 +0300
                Re: how to get the ordinal number in list Robin Becker <robin@reportlab.com> - 2014-08-11 15:32 +0100
                Re: how to get the ordinal number in list Terry Reedy <tjreedy@udel.edu> - 2014-08-11 18:01 -0400
                Re: how to get the ordinal number in list Chris Angelico <rosuav@gmail.com> - 2014-08-12 09:27 +1000
                Re: how to get the ordinal number in list wxjmfauth@gmail.com - 2014-08-12 00:21 -0700
                Re: how to get the ordinal number in list alister <alister.nospam.ware@ntlworld.com> - 2014-08-12 10:40 +0000
                Re: how to get the ordinal number in list Chris Angelico <rosuav@gmail.com> - 2014-08-12 23:39 +1000
                Re: how to get the ordinal number in list alister <alister.nospam.ware@ntlworld.com> - 2014-08-12 18:45 +0000
                Re: how to get the ordinal number in list Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-08-12 20:16 +0100
                Re: how to get the ordinal number in list "Neil D. Cerutti" <neilc@norwich.edu> - 2014-08-12 13:40 -0400
                Re: how to get the ordinal number in list Rustom Mody <rustompmody@gmail.com> - 2014-08-12 11:20 -0700
                Re: how to get the ordinal number in list "Neil D. Cerutti" <neilc@norwich.edu> - 2014-08-12 15:29 -0400
                Re: how to get the ordinal number in list Rustom Mody <rustompmody@gmail.com> - 2014-08-12 20:49 -0700
                Re: how to get the ordinal number in list Terry Reedy <tjreedy@udel.edu> - 2014-08-12 18:01 -0400
              Re: how to get the ordinal number in list Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-08-11 13:00 +1000
                Re: how to get the ordinal number in list Rustom Mody <rustompmody@gmail.com> - 2014-08-10 21:29 -0700
                Re: how to get the ordinal number in list Steven D'Aprano <steve@pearwood.info> - 2014-08-11 10:28 +0000
                Re: how to get the ordinal number in list Rustom Mody <rustompmody@gmail.com> - 2014-08-11 04:49 -0700
                Re: how to get the ordinal number in list Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-08-13 12:11 +1000
                Re: how to get the ordinal number in list Chris Angelico <rosuav@gmail.com> - 2014-08-13 12:18 +1000
                Re: how to get the ordinal number in list Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-08-13 13:11 +1000
          Re: how to get the ordinal number in list Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-08-11 03:17 +1000

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