Chooses k unique random elements from a population sequence with odds like random.sample

sample.py

# coding=utf-8

import random

__author__ = "[email protected]"


def sample(population, k, odds=lambda item: 1.0):
    """
    Chooses k unique random elements from a population sequence with odds.

    like random.sample
    """
    result = [None] * k
    selected = set()
    size = len(population)
    for i in range(k):
        while True:
            pos = int(size * random.random())
            if pos in selected:
                continue
            target = population[pos]
            if odds(target) >= random.random():
                selected.add(pos)
                result[i] = target
                break
    return result