(Python) algorithm to randomly select a key based on proportionality/weight

Question

I\'m a bit at a loss as to how to find a clean algorithm for doing the following:

Suppose I have a dict k:

>>> k = {\'A\': 68, \'B\': 62, \'         


        

Answer 1

I've developed an algorithm a few years ago, with application in Perl and SQL, you can read about it here, complete with analysis and tests why it (most likely) is correct.

The concept is simple: for each item, pick a random number, pull it through some function that depends on the items' weight, and pick the item with the lowest value.

That function is:

x[i] = -log(1 - rand())/weight[i]