# [Tutor] Random module.. or?

Bob Gailer bgailer at alum.rpi.edu
Tue Aug 7 21:37:32 CEST 2007

```Tony Noyeaux wrote:
> As always, thanks all for the ongoing help and suggestions... the
> learning continues.
>
> I've successfully made a number of programs, making use of various
> random code.
>
> Using random.choice etc
> #-----------------------------------
> import random
> letters = ('a', 'b', 'c', 'd')
> a = random.choice(letters)
> print 'your random letter is %s' %(a)
> #------------------------------------
> or
> #------------------------------------
> import random
> letters = ('a', 'a', 'b', 'b', 'c', 'd')
> a = random.choice(letters)
> print 'your random letter is %s' %(a)
> #-----------------------------------
>
> In the first random... , each abcd, has a equal chance of coming out.
> In the 2nd random,... a b,.. have an extra chance vs c/d to come out,
> making them more likely.
>
> What i would like to experiment now with is,...
>
> How can you control randomness... lets say for fish.
>
> CatfishBreedA
> Can be say, 4inches, to 24inches long
> Most fish caught are say 7-14inches long
> Maybe 1 in 1000 catfish caught are say, 16-20 inches long
> Maybe 1 in 10000 catfish caught are say, 20inches +
>
> How.. can you program that kind of randomness?
>
> Or another way to look at it.
>
> Can score 4-45pts a game.
> Most games, he scores 15-25 pts
> Maybe 1 in 1000 games he scores 30 plus pts
> Maybe 1 in 10000 he scores 45 pts.
>
> The actual %'s, lengths, and pts are irrelevent,.. they are just used
> to as an example.
>
>
> Any guidance would be appreciated.
10000 games would  be distributed thus:
1 = 45 pts
10 = 30+ pts
99989 = 15-25 pts
so generate a random integer between 1 and 10000.
if it is <= 1 then 45
else if it is <= 11 then 30+
else 15-25

Enough to get you going?

--
Bob Gailer
510-978-4454 Oakland, CA
919-636-4239 Chapel Hill, NC

```