On Sat, Jul 17, 2010 at 11:48 PM, Richard D. Moores <rdmoo...@gmail.com> wrote: > On Sat, Jul 17, 2010 at 13:56, Dave Angel <da...@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) _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
