Processing a file using multithreads

Dave Angel davea at
Thu Sep 8 21:34:16 EDT 2011

On 01/-10/-28163 02:59 PM, Abhishek Pratap wrote:
> Hi Guys
> My experience with python is 2 days and I am looking for a slick way
> to use multi-threading to process a file. Here is what I would like to
> do which is somewhat similar to MapReduce in concept.
> # test case
> 1. My input file is 10 GB.
> 2. I want to open 10 file handles each handling 1 GB of the file
> 3. Each file handle is processed in by an individual thread using the
> same function ( so total 10 cores are assumed to be available on the
> machine)
> 4. There will be 10 different output files
> 5. once the 10 jobs are complete a reduce kind of function will
> combine the output.
> Could you give some ideas ?
> So given a file I would like to read it in #N chunks through #N file
> handles and process each of them separately.
> Best,
> -Abhi
You should probably forget threads, and simply do them as 10 separate 
processes, all launched by a single parent.  Since they don't share any 
state, there's no need to get the inefficiency of threads.


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