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Re: fseek In Compressed Files

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From Peter Otten <__peter__@web.de>
Subject Re: fseek In Compressed Files
Date Thu, 30 Jan 2014 17:21:28 +0100
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Serhiy Storchaka wrote:

> 30.01.14 13:28, Peter Otten написав(ла):
>> Ayushi Dalmia wrote:
>>
>>> I need to randomly access a bzip2 or gzip file. How can I set the offset
>>> for a line and later retreive the line from the file using the offset.
>>> Pointers in this direction will help.
>>
>> with gzip.open(filename) as f:
>>      f.seek(some_pos)
>>      print(f.readline())
>>      f.seek(some_pos)
>>      print(f.readline())
>>
>> seems to work as expected. Can you tell a bit more about your usecase (if
>> it isn't covered by that basic example)?
> 
> I don't recommend to seek backward in compressed file. This is very
> inefficient operation.

Do you know an efficient way to implement random access for a bzip2 or gzip 
file?

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Thread

fseek In Compressed Files Ayushi Dalmia <ayushidalmia2604@gmail.com> - 2014-01-30 02:50 -0800
  Re: fseek In Compressed Files Peter Otten <__peter__@web.de> - 2014-01-30 12:28 +0100
  Re:fseek In Compressed Files Dave Angel <davea@davea.name> - 2014-01-30 06:55 -0500
  Re: fseek In Compressed Files Ayushi Dalmia <ayushidalmia2604@gmail.com> - 2014-01-30 05:34 -0800
    Re: fseek In Compressed Files Chris Angelico <rosuav@gmail.com> - 2014-01-31 00:49 +1100
    Re: fseek In Compressed Files Dave Angel <davea@davea.name> - 2014-02-03 15:57 -0500
      Re: fseek In Compressed Files Ayushi Dalmia <ayushidalmia2604@gmail.com> - 2014-02-04 04:39 -0800
  Re: fseek In Compressed Files Serhiy Storchaka <storchaka@gmail.com> - 2014-01-30 17:02 +0200
  Re: fseek In Compressed Files Ayushi Dalmia <ayushidalmia2604@gmail.com> - 2014-01-30 07:37 -0800
    Re: fseek In Compressed Files Dave Angel <davea@davea.name> - 2014-01-30 13:46 -0500
      Re: fseek In Compressed Files Ayushi Dalmia <ayushidalmia2604@gmail.com> - 2014-01-31 21:52 -0800
        Re: fseek In Compressed Files Dave Angel <davea@davea.name> - 2014-02-01 04:38 -0500
  Re: fseek In Compressed Files Peter Otten <__peter__@web.de> - 2014-01-30 17:21 +0100
    Re: fseek In Compressed Files Ayushi Dalmia <ayushidalmia2604@gmail.com> - 2014-01-31 21:50 -0800
  Re: fseek In Compressed Files Serhiy Storchaka <storchaka@gmail.com> - 2014-02-03 20:32 +0200

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