[Tutor] permutations, patterns, and probability

[Kent Johnson]

kevin parks wrote:
> Tremendously helpful!!!! One question though. How can i pluck a unique 
> item from my exhaustive list of permutations without repeats making sure 
> that each one is used once? Like filling a bag, shaking it, and then 
> picking from the bag and removing that item from the bag so it isn't 
> used again....

Use random.shuffle() to 'shake' the list. Then use pop() to remove an item:

  >>> import random
  >>> l=range(10)
  >>> random.shuffle(l)
  >>> l
[4, 5, 0, 8, 9, 6, 2, 1, 7, 3]
  >>> l.pop()
3
  >>> l.pop()
7
  >>> l.pop()
1
  >>> l
[4, 5, 0, 8, 9, 6, 2]

Kent