[Tutor] A file containing a string of 1 billion random digits.

Richard D. Moores rdmoores at gmail.com
Mon Jul 19 09:50:27 CEST 2010

On Sun, Jul 18, 2010 at 16:11, Alan Gauld <alan.gauld at btinternet.com> wrote:
> "Richard D. Moores" <rdmoores at gmail.com> wrote
>>>> I earlier reported that my laptop couldn't handle even 800 million.
>>> What do you mean, "couldn't handle"? Couldn't handle 800 million of
>>> what? Obviously not bytes,
>> I meant what the context implied. Bytes. Look back in this thread to
>> see my description of my laptop's problems.
> But you stored those in a list and then joined the list which meant you
> actually at one point had two copies of the data, one in the list and
> one in the string - that's >1.6billion bytes.
> And these tests suggest you only get about 2billion bytes of memory
> to use which maybe explains why you were pushed to the limit at
> 800million.

Ah. Maybe it does. Thanks, Alan.

Following Dave Angel's info about the swap file, I took a look at my
64-bit Vista paging file size. The custom setting was 5944 MB. Without
really thinking that it would help, I changed the size to 8000 MB and
rebooted. I then tried my searching script
(<http://tutoree7.pastebin.com/rJ1naffZ>) on the 1 billion random
digits file, changing script lines 32 and 48 appropriately. As before,
this froze my laptop and I had to do an abrupt, forced shutdown. Don't
want to do too many of those.

Now, I don't really care about what a billion random digits might
contain. The first billion digits of pi, maybe -- but the most I have
so far is 100 million. If I can get gmpy to give me 900 million more,
then I'll try to figure out how to do your trick of getting one or two
small chunks at a time for searching. I do want to learn that stuff
(tell, seek, etc.), but I need to follow along in a good elementary
book first, I think.


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