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Re: How can I speed up a script that iterates over a large range (600 billion)?

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Chris Torek <nospam@torek.net> writes:
> def primes():
>     """
>     Yields sequence of prime numbers via Sieve of Eratosthenes.
>     """

I think this has the same order-complexity but is enormously slower in
practice, and runs out of recursion stack after a while.  Exercise: spot
the recursion.

    from itertools import islice, ifilter, count

    def primes():
        a = count(2)
        while True:
            p = a.next()
            yield p
            a = ifilter(lambda t,p=p: t%p, a)

    # print first 100 primes
    print list(islice(primes(), 100))

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How can I speed up a script that iterates over a large range (600 billion)? John Salerno <johnjsal@gmail.com> - 2011-06-21 12:48 -0700
  Re: How can I speed up a script that iterates over a large range (600 billion)? Ian Kelly <ian.g.kelly@gmail.com> - 2011-06-21 14:02 -0600
  Re: How can I speed up a script that iterates over a large range (600 billion)? Irmen de Jong <irmen@-NOSPAM-xs4all.nl> - 2011-06-21 22:10 +0200
    sorry, possibly too much info. was: Re: How can I speed up a script that iterates over a large range (600 billion)? Irmen de Jong <irmen@-NOSPAM-xs4all.nl> - 2011-06-21 22:22 +0200
      Re: sorry, possibly too much info. was: Re: How can I speed up a script that iterates over a large range (600 billion)? John Salerno <johnjsal@gmail.com> - 2011-06-21 14:09 -0700
        Re: sorry, possibly too much info. was: Re: How can I speed up a script that iterates over a large range (600 billion)? Irmen de Jong <irmen.NOSPAM@xs4all.nl> - 2011-06-21 23:39 +0200
        Re: sorry, possibly too much info. was: Re: How can I speed up a script that iterates over a large range (600 billion)? Ian Kelly <ian.g.kelly@gmail.com> - 2011-06-21 15:41 -0600
          Re: sorry, possibly too much info. was: Re: How can I speed up a script that iterates over a large range (600 billion)? John Salerno <johnjsal@gmail.com> - 2011-06-21 14:48 -0700
        Re: sorry, possibly too much info. was: Re: How can I speed up a script that iterates over a large range (600 billion)? Vlastimil Brom <vlastimil.brom@gmail.com> - 2011-06-21 23:33 +0200
        Re: sorry, possibly too much info. was: Re: How can I speed up a script that iterates over a large range (600 billion)? Paul Rubin <no.email@nospam.invalid> - 2011-06-21 17:05 -0700
          Re: sorry, possibly too much info. was: Re: How can I speed up a script that iterates over a large range (600 billion)? John Salerno <johnjsal@gmail.com> - 2011-06-21 18:21 -0700
            Re: sorry, possibly too much info. was: Re: How can I speed up a script that iterates over a large range (600 billion)? Paul Rubin <no.email@nospam.invalid> - 2011-06-21 19:09 -0700
              Re: sorry, possibly too much info. was: Re: How can I speed up a script that iterates over a large range (600 billion)? John Salerno <johnjsal@gmail.com> - 2011-06-21 20:02 -0700
                Re: sorry, possibly too much info. was: Re: How can I speed up a script that iterates over a large range (600 billion)? Irmen de Jong <irmen.NOSPAM@xs4all.nl> - 2011-06-22 19:46 +0200
            Re: sorry, possibly too much info. was: Re: How can I speed up a script that iterates over a large range (600 billion)? MRAB <python@mrabarnett.plus.com> - 2011-06-22 03:10 +0100
            Re: sorry, possibly too much info. was: Re: How can I speed up a script that iterates over a large range (600 billion)? Mel <mwilson@the-wire.com> - 2011-06-21 23:02 -0400
              Re: sorry, possibly too much info. was: Re: How can I speed up a script that iterates over a large range (600 billion)? John Salerno <johnjsal@gmail.com> - 2011-06-21 20:41 -0700
  Re: How can I speed up a script that iterates over a large range (600 billion)? Mel <mwilson@the-wire.com> - 2011-06-21 16:19 -0400
    Re: How can I speed up a script that iterates over a large range (600 billion)? Tim Roberts <timr@probo.com> - 2011-06-22 23:21 -0700
  Re: How can I speed up a script that iterates over a large range (600 billion)? MRAB <python@mrabarnett.plus.com> - 2011-06-21 21:26 +0100
  Re: How can I speed up a script that iterates over a large range (600 billion)? Terry Reedy <tjreedy@udel.edu> - 2011-06-21 19:30 -0400
    Re: How can I speed up a script that iterates over a large range (600 billion)? Paul Rubin <no.email@nospam.invalid> - 2011-06-21 17:00 -0700
      Re: How can I speed up a script that iterates over a large range (600 billion)? Terry Reedy <tjreedy@udel.edu> - 2011-06-22 00:18 -0400
        Re: How can I speed up a script that iterates over a large range (600 billion)? Paul Rubin <no.email@nospam.invalid> - 2011-06-21 22:32 -0700
          Re: How can I speed up a script that iterates over a large range (600 billion)? Terry Reedy <tjreedy@udel.edu> - 2011-06-22 18:46 -0400
  Re: How can I speed up a script that iterates over a large range (600 billion)? Benjamin Kaplan <benjamin.kaplan@case.edu> - 2011-06-21 20:07 -0700
  Re: How can I speed up a script that iterates over a large range (600 billion)? Chris Torek <nospam@torek.net> - 2011-06-22 05:58 +0000
    Re: How can I speed up a script that iterates over a large range (600 billion)? Paul Rubin <no.email@nospam.invalid> - 2011-06-21 23:23 -0700
      Re: How can I speed up a script that iterates over a large range (600 billion)? Slaunger <slaunger@gmail.com> - 2011-06-23 02:52 -0700
    Re: How can I speed up a script that iterates over a large range (600 billion)? Ian Kelly <ian.g.kelly@gmail.com> - 2011-06-22 01:16 -0600
    Re: How can I speed up a script that iterates over a large range (600 billion)? Anny Mous <b1540457@tyldd.com> - 2011-06-22 22:01 +1000
      Re: How can I speed up a script that iterates over a large range (600 billion)? Chris Angelico <rosuav@gmail.com> - 2011-06-22 22:28 +1000
      Re: How can I speed up a script that iterates over a large range (600 billion)? Ian Kelly <ian.g.kelly@gmail.com> - 2011-06-22 09:52 -0600
    Re: How can I speed up a script that iterates over a large range (600 billion)? MRAB <python@mrabarnett.plus.com> - 2011-06-22 16:33 +0100

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