How can I get a weighted random pick from Python's Counter class?

Question

I have a program where I\'m keeping track of the success of various things using collections.Counter — each success of a thing increments the corr

Answer 1

Another variant, Setup is a bit cumbersome, but lookup is in logarithmic complexity (suitable when several lookups are needed):

import itertools
import random
from collections import Counter
from bisect import bisect

counter = Counter({"a": 5, "b": 1, "c": 1})

#setup
most_common = counter.most_common()
accumulated = list(itertools.accumulate([x[1] for x in most_common])) # i.e. [5, 6, 7]
total_size = accumulated[-1]

# lookup
i = random.randrange(total_size)
print(most_common[bisect(accumulated, i)])