ValueError：样本大于总体或为负（n=5）答案

【问题标题】：ValueError: Sample larger than population or is negative (with n=5)ValueError：样本大于总体或为负（n=5）
【发布时间】：2021-11-11 14:29:12
【问题描述】：

我编写了一个代码来随机获取一组人。目的是当一个人已经被随机选择时，程序应该删除他。我使用了random.sample() 函数，当我达到 5 时它对n=1,2,3,4 工作得很好，它给了我一个错误，直到现在我试图了解这个函数背后发生了什么。任何解释和提示都会有所帮助。谢谢！

import random
ma_list =["anne","aline","gros","eve","armand","yves","elv","allo","sonia","luc","marc","jules","kevin"]
#this will contain an occurence of our list
maListOc = ma_list
#this list will contain our random list
random_list = None
groupe = 1
#for each element in ma_list, we randome and put into our variable
for i in ma_list:
    random_list = random.sample(ma_list, 5)
    #then we remove data already randomize in our list, but the complexity is high for this little program
    for element in random_list:
        ma_list.remove(element)
    print("Goupe N°:",groupe)
    #and we finally print our randomized list 
    print(random_list)
    print("______________________________")
    groupe += 1
print(maListOc)

这是输出：

Goupe N°: 1
['aline', 'gros', 'armand', 'sonia', 'anne']
______________________________
Goupe N°: 2
['kevin', 'allo', 'eve', 'elv', 'marc']
______________________________
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-29-c2d13d61c8d1> in <module>
      8 #for each element in ma_list, we randome and put into our variable
      9 for i in ma_list:
---> 10     random_list = random.sample(ma_list, 5)
     11     #then we remove data already randomize in our list, but the complexity is high for this little program
     12     for element in random_list:

~\anaconda3\lib\random.py in sample(self, population, k)
    361         n = len(population)
    362         if not 0 <= k <= n:
--> 363             raise ValueError("Sample larger than population or is negative")
    364         result = [None] * k
    365         setsize = 21        # size of a small set minus size of an empty list

ValueError: Sample larger than population or is negative

【问题讨论】：

我不确定有什么不清楚的地方。您正在从 ma_list 中删除项目，直到它少于 5 个项目。那你就不能再随机选择5个了。
经过 2 次迭代，只剩下 3 个名称。所以样本不能从 3 个列表项中取出 5 个名称。
我现在明白了，所以如果我想每组有五个人，我应该增加项目的数量。谢谢
当我这样做的时候，我只是在说如果我想在每个组中有 5 个或更多，会发生什么。大声笑

标签： python random

【解决方案1】：

错误显示ma_list的len小于5，需要添加if...来打破for循环。

import random
ma_list =["anne","aline","gros","eve","armand","yves","elv","allo","sonia","luc","marc","jules","kevin"]
#this will contain an occurence of our list
maListOc = ma_list
#this list will contain our random list
random_list = None
groupe = 1
#for each element in ma_list, we randome and put into our variable
for i in ma_list:
    if(len(ma_list)<=5):
        break
    random_list = random.sample(ma_list, 5)
    #then we remove data already randomize in our list, but the complexity is high for this little program
    for element in random_list:
        ma_list.remove(element)
    print("Goupe N°:",groupe)
    #and we finally print our randomized list 
    print(random_list)
    print("______________________________")
    groupe += 1
print(maListOc)

输出：

Goupe N°: 1
['aline', 'jules', 'marc', 'yves', 'luc']
______________________________
Goupe N°: 2
['kevin', 'armand', 'gros', 'anne', 'sonia']
______________________________
['eve', 'elv', 'allo']

【讨论】：

是的，你是对的，我应该更加注意这个错误。谢谢