从列表中随机选择 50 个项目

小编典典

从列表中随机选择 50 个项目

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我有一个从文件中读取项目列表的函数。如何从列表中随机选择 50 个项目以写入另一个文件？

def randomizer(input, output='random.txt'):
    query = open(input).read().split()
    out_file = open(output, 'w')

    random.shuffle(query)

    for item in query:
        out_file.write(item + '\n')

例如，如果总随机化文件是

random_total = ['9', '2', '3', '1', '5', '6', '8', '7', '0', '4']

我想要一个随机的 3 组，结果可能是

random = ['9', '2', '3']

如何从我随机化的列表中选择 50 个？

更好的是，我如何从原始列表中随机选择 50 个？

阅读 56

2022-08-19

共1个答案

小编典典

如果列表是随机顺序的，您可以只取前 50 个。

否则，使用

import random
random.sample(the_list, 50)

random.sample帮助文本：

sample(self, population, k) method of random.Random instance
    Chooses k unique random elements from a population sequence.

    Returns a new list containing elements from the population while
    leaving the original population unchanged.  The resulting list is
    in selection order so that all sub-slices will also be valid random
    samples.  This allows raffle winners (the sample) to be partitioned
    into grand prize and second place winners (the subslices).

    Members of the population need not be hashable or unique.  If the
    population contains repeats, then each occurrence is a possible
    selection in the sample.

    To choose a sample in a range of integers, use xrange as an argument.
    This is especially fast and space efficient for sampling from a
    large population:   sample(xrange(10000000), 60)

2022-08-19