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

[Hugo Arts]

On Sat, Jul 17, 2010 at 11:48 PM, Richard D. Moores <rdmoores at gmail.com> wrote:
> On Sat, Jul 17, 2010 at 13:56, Dave Angel <davea at ieee.org> wrote:
>> Your concern over a leading zero applies equally to two leading zeroes, or
>> three, or whatever.
>
> I don't think so. Look again at my function, randIntOfGivenLength().
> Try a for loop with it, say with randIntOfGivenLength(9) and looping
> 100 times:
>
> for x in range(100):
>     n = randIntOfGivenLength(9)
>     n = str(n)
>     print(n)
>
> You'll see that all strings have 9 digits. The problem is that none of
> them begin with "0". These are just strings of almost-random digits,
> and in the script I give the 1st digit a chance to be a "0" by
> prepending a digit -- just one -- chosen by random.choice() from the
> string "0123456789".
>

This is great, but now your *second* digit will never be zero. So your
strings are still "almost" random.

<rant> Look, randomness is complicated. It's crap like this that trips
up even cryptographers all the time. I know you won't need your digits
for security or anything, but if you're concerned that the first digit
of a sequence is never zero, you should be equally concerned by the
second digit not being zero. It's the same amount of non-randomness,
and your 'solution' just moves the problem around, it doesn't solve
anything. </rant>

Hugo

P.S.: I just thought of this: how about generating numbers that are
one digit too long, and removing the first digit instead of adding an
extra one? It just gets rid of the digit exhibiting non-randomness
altogether. (disclaimer: IANA cryptanalyst, so there may be equally
many things wrong with this)