Re: seek operation in python

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From	Cecil Westerhof <Cecil@decebal.nl>
Newsgroups	comp.lang.python
Subject	Re: seek operation in python
Organization	Decebal Computing
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Date	Thu, 30 Apr 2015 08:27:29 +0200
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Op Thursday 30 Apr 2015 02:33 CEST schreef Chris Angelico:

> On Thu, Apr 30, 2015 at 4:08 AM, siva sankari R <buddingrose11@gmail.com> wrote:
>> file=open("input","r")
>> line=file.seek(7)
>> print line
>>
>> The above code is supposed to print a line but it prints "none". I
>> don't know where the mistake is. Help.!
>
> Going right back to the beginning... Are you aware that 'seek' works
> with byte positions? On a text file, you can't even do this, and
> even on a byte file, it won't give you the seventh line.
>
> If, as you say, it's only some eighty lines of code, the best
> solution is probably the simplest: read the whole file into memory.
>
> with open("input.cpp") as f:
> lines = f.readlines()
> print(lines[7])

Is the following not better:
    print(open('input.cpp', 'r').readlines()[7])

Time is the same (about 25 seconds for 100.000 calls), but I find this
more clear.

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof

Thread

seek operation in python siva sankari R <buddingrose11@gmail.com> - 2015-04-29 11:08 -0700
  Re: seek operation in python Joel Goldstick <joel.goldstick@gmail.com> - 2015-04-29 14:17 -0400
    Re: seek operation in python siva sankari R <buddingrose11@gmail.com> - 2015-04-29 11:26 -0700
      Re: seek operation in python Billy Earney <billy.earney@gmail.com> - 2015-04-29 13:42 -0500
      Re: seek operation in python Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-04-29 21:53 +0100
        Re: seek operation in python Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-30 10:19 +1000
  Re: seek operation in python MRAB <python@mrabarnett.plus.com> - 2015-04-29 19:50 +0100
  Re: seek operation in python John Gordon <gordon@panix.com> - 2015-04-29 18:53 +0000
  Re: seek operation in python Chris Angelico <rosuav@gmail.com> - 2015-04-30 10:33 +1000
    Re: seek operation in python Cecil Westerhof <Cecil@decebal.nl> - 2015-04-30 08:27 +0200
      Re: seek operation in python Chris Angelico <rosuav@gmail.com> - 2015-04-30 17:33 +1000
        Re: seek operation in python Cecil Westerhof <Cecil@decebal.nl> - 2015-04-30 10:06 +0200
          Re: seek operation in python Dave Angel <davea@davea.name> - 2015-04-30 04:31 -0400
            Re: seek operation in python Cecil Westerhof <Cecil@decebal.nl> - 2015-04-30 11:06 +0200
              Re: seek operation in python Chris Angelico <rosuav@gmail.com> - 2015-04-30 19:39 +1000
          Re: seek operation in python Larry Hudson <orgnut@yahoo.com> - 2015-04-30 12:38 -0700
            Re: seek operation in python Cecil Westerhof <Cecil@decebal.nl> - 2015-04-30 22:50 +0200
              Re: seek operation in python Larry Hudson <orgnut@yahoo.com> - 2015-04-30 19:42 -0700
  Re: seek operation in python Cecil Westerhof <Cecil@decebal.nl> - 2015-04-30 14:31 +0200

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