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Groups > comp.lang.python > #63905

Re: Python Fast I/o

References <a9c545f2-fbc3-4ac4-81ee-a91f61c72b84@googlegroups.com>
Date 2014-01-15 01:03 +1100
Subject Re: Python Fast I/o
From Chris Angelico <rosuav@gmail.com>
Newsgroups comp.lang.python
Message-ID <mailman.5458.1389708197.18130.python-list@python.org> (permalink)

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On Wed, Jan 15, 2014 at 12:50 AM, Ayushi Dalmia
<ayushidalmia2604@gmail.com> wrote:
> I need to write into a file for a project which will be evaluated on the basis of time. What is the fastest way to write 200 Mb of data, accumulated as a list into a file.
>
> Presently I am using this:
>
> with open('index.txt','w') as f:
>       f.write("".join(data))
>       f.close()

with open('index.txt','w') as f:
    for hunk in data:
        f.write(hunk)

You don't need to f.close() - that's what the 'with' block guarantees.
Iterating over data and writing each block separately means you don't
have to first build up a 200MB string. After that, your performance is
going to be mainly tied to the speed of your disk, not anything that
Python can affect.

ChrisA

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Thread

Python Fast I/o Ayushi Dalmia <ayushidalmia2604@gmail.com> - 2014-01-14 05:50 -0800
  Re: Python Fast I/o Chris Angelico <rosuav@gmail.com> - 2014-01-15 01:03 +1100
    Re: Python Fast I/o Ayushi Dalmia <ayushidalmia2604@gmail.com> - 2014-01-14 06:24 -0800
      Re: Python Fast I/o Chris Angelico <rosuav@gmail.com> - 2014-01-15 01:32 +1100
      Re: Python Fast I/o Roy Smith <roy@panix.com> - 2014-01-14 09:40 -0500
  Re: Python Fast I/o Tim Chase <python.list@tim.thechases.com> - 2014-01-14 08:18 -0600

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