ValueError: Sample larger than population or is negative (with n=5)

Question

我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，它在 n=1,2,3,4 上运行良好，当我达到 5 时，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的事情。任何解释和提示都会有帮助。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

Answer 1

错误显示 ma_list 的 len 小于 5。您需要添加如下 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']