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Re: looking for a neat solution to a nested loop problem

From 88888 Dihedral <dihedral88888@googlemail.com>
Newsgroups comp.lang.python
Subject Re: looking for a neat solution to a nested loop problem
Date 2012-08-14 14:08 -0700
Organization http://groups.google.com
Message-ID <0207a924-6c0c-42eb-9f1e-3a07bb3097b1@googlegroups.com> (permalink)
References (1 earlier) <pan.2012.08.06.16.18.08.86000@nowhere.com> <a8acciFcukU1@mid.individual.net> <mailman.3022.1344276685.4697.python-list@python.org> <LsOdnTFsmezHDr3NnZ2dnUVZ5h6dnZ2d@giganews.com> <pan.2012.08.07.15.32.54.912000@nowhere.com>

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Nobody於 2012年8月7日星期二UTC+8下午11時32分55秒寫道:
> On Mon, 06 Aug 2012 21:02:33 -0700, Larry Hudson wrote:
> 
> 
> 
> >>       for i in range(N,N+100):
> 
> >>           for j in range(M,M+100):
> 
> >>               do_something(i % 100 ,j % 100)
> 
> >>
> 
> >> Emile
> 
> > 
> 
> > How about...
> 
> > 
> 
> > for i in range(100):
> 
> >      for j in range(100):
> 
> >          do_something((i + N) % 100, (j + M) % 100)
> 
> 
> 
> Both of these approaches move the modifications to the sequence into the
> 
> body of the loop. It may be preferable to iterate over the desired
> 
> sequence directly. E.g.
> 
> 
> 
> 	for i in ((N + ii) % 100 for ii in xrange(100)):
> 
> 	    for j in ((M + jj) % 100 for jj in xrange(100)):
> 
> 	        do_something(i, j)

I'll contrubute another version by the xrange function in python.

for i in xrange(N, N+100): # not list based
    if i<100: i2=i else: i2=i-100 # not in the inner most loop
    for j in xrange(M, M+100):
        if j<100: j2=j else: j2=j-100
        do_something(i2,j2)


        

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Thread

looking for a neat solution to a nested loop problem Tom P <werotizy@freent.dd> - 2012-08-06 17:52 +0200
  Re: looking for a neat solution to a nested loop problem John Gordon <gordon@panix.com> - 2012-08-06 16:03 +0000
    Re: looking for a neat solution to a nested loop problem Tom P <werotizy@freent.dd> - 2012-08-06 19:16 +0200
      Re: looking for a neat solution to a nested loop problem Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-08-07 01:27 +0000
  Re: looking for a neat solution to a nested loop problem Ian Foote <ian@feete.org> - 2012-08-06 17:07 +0100
  Re: looking for a neat solution to a nested loop problem Ethan Furman <ethan@stoneleaf.us> - 2012-08-06 09:15 -0700
  Re: looking for a neat solution to a nested loop problem Nobody <nobody@nowhere.com> - 2012-08-06 17:18 +0100
    Re: looking for a neat solution to a nested loop problem Tom P <werotizy@freent.dd> - 2012-08-06 19:14 +0200
      Re: looking for a neat solution to a nested loop problem Emile van Sebille <emile@fenx.com> - 2012-08-06 11:11 -0700
        Re: looking for a neat solution to a nested loop problem Larry Hudson <orgnut@yahoo.com> - 2012-08-06 21:02 -0700
          Re: looking for a neat solution to a nested loop problem Nobody <nobody@nowhere.com> - 2012-08-07 16:32 +0100
            Re: looking for a neat solution to a nested loop problem 88888 Dihedral <dihedral88888@googlemail.com> - 2012-08-07 18:42 -0700
            Re: looking for a neat solution to a nested loop problem 88888 Dihedral <dihedral88888@googlemail.com> - 2012-08-09 11:46 -0700
            Re: looking for a neat solution to a nested loop problem 88888 Dihedral <dihedral88888@googlemail.com> - 2012-08-09 11:39 -0700
            Re: looking for a neat solution to a nested loop problem 88888 Dihedral <dihedral88888@googlemail.com> - 2012-08-14 14:08 -0700
      Re: looking for a neat solution to a nested loop problem Grant Edwards <invalid@invalid.invalid> - 2012-08-06 18:25 +0000
        Re: looking for a neat solution to a nested loop problem Grant Edwards <invalid@invalid.invalid> - 2012-08-06 18:29 +0000
          Re: looking for a neat solution to a nested loop problem Tom P <werotizy@freent.dd> - 2012-08-06 21:03 +0200
            Re: looking for a neat solution to a nested loop problem Grant Edwards <invalid@invalid.invalid> - 2012-08-06 19:22 +0000
              Re: looking for a neat solution to a nested loop problem Emile van Sebille <emile@fenx.com> - 2012-08-06 12:52 -0700
  Re: looking for a neat solution to a nested loop problem André Malo <ndparker@gmail.com> - 2012-08-06 20:19 +0200
  Re: looking for a neat solution to a nested loop problem Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-08-06 15:31 -0400
  Re: looking for a neat solution to a nested loop problem Arnaud Delobelle <arnodel@gmail.com> - 2012-08-06 21:14 +0100

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