Top k most frequent

Find the k values that appear most often in a list. Count each value with a dictionary, then rank the (value, count) pairs: highest count first, and when counts tie, the smaller value first. sorted or heapq.nsmallest can do the ranking if you give them a key that returns (-count, value); the minus sign makes bigger counts come first.

Write most_frequent(items, k) that returns the k most frequent values as a list, most frequent first. Ties are broken by the value itself in ascending order. k never exceeds the number of distinct values.

most_frequent(["a", "b", "a", "c", "b", "a"], 2)  ->  ["a", "b"]
most_frequent([3, 1, 3, 1, 2], 2)                 ->  [1, 3]

import heapq

def most_frequent(items, k):
    ...