Choosing items from a list on a percentual basis

Question

I have a list with around 40 strings and want to assign every item a weight / percentage. During runtime I now want a randomizer to pick an item from the list according to its percentage. Meaning that over a large enough sample size the number of times this item gets picked would correspond to the assigned percentage. A problem that I'm facing is that in the future I might want to extend the list and would then have to assign a new percentage to other items. What would be the best way to save this list and assign weights to individual items?

I can think of some ways to implement this but they are all rather quick & dirty so I was hoping somebody has a design pattern in mind. I'm working in Python but since this is conceptual I'm not really fishing for explicit examples.

Thank you so much for your help.

Answer 1

Check out this page: Weighted random generation in Python

Edit: See this also (on SO): A weighted version of random.choice