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Tim Chase <python.list at tim.thechases.com> writes: > I'm not coming up with the right keywords to find what I'm hunting. > I'd like to randomly sample a modestly compact list with weighted > distributions, so I might have > > data = ( > ("apple", 20), > ("orange", 50), > ("grape", 30), > ) That's not a list, it's a tuple. I think you want a list. When you want a sequence where each position has a semantic meaning, use a tuple (such as ?("apple", 20)?). Each item has a meaning *because of* the position it's in; if the items were in a different order, they'd mean different things. When you want a sequence where the positions don't have a special meaning ? each item means exactly the same no matter if you change the order ? that's sometimes called a ?homogeneous? sequence, and you want a list. So a ?record? should be represented as a tuple, and a ?table? of records should be represented as a list of tuples: records = [ ("apple", 20), ("orange", 50), ("grape", 30), ] > and I'd like to random.sample() it as if it was a 100-element list. The implication being, I suppose, that you'd like the number in each tuple to be a weighting for the probability of choosing that item. For probability weightings, you should arrange for the weightings to sum to 1 (instead of 100 in your example). Then each weighting is simply the desired probability of that item, and those values will work with various libraries that deal with probability. > What am I missing? (links to relevant keywords/searches/algorithms > welcome in lieu of actually answering in-line) You're looking for a ?probability distribution? and ?weighted choice?. Hope that helps! -- \ ?This world in arms is not spending money alone. It is spending | `\ the sweat of its laborers, the genius of its scientists, the | _o__) hopes of its children.? ?Dwight Eisenhower, 1953-04-16 | Ben Finney

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