The Python Oracle

Select 50 items from list at random

Become part of the top 3% of the developers by applying to Toptal https://topt.al/25cXVn

--

Music by Eric Matyas
https://www.soundimage.org
Track title: Life in a Drop

--

Chapters
00:00 Question
00:51 Accepted answer (Score 383)
01:28 Answer 2 (Score 51)
01:44 Answer 3 (Score 43)
02:04 Answer 4 (Score 2)
02:52 Thank you

--

Full question
https://stackoverflow.com/questions/1551...

--

Content licensed under CC BY-SA
https://meta.stackexchange.com/help/lice...

--

Tags
#python #list #select #random

#avk47



ACCEPTED ANSWER

Score 405


If the list is in random order, you can just take the first 50.

Otherwise, use

import random
random.sample(the_list, 50)

random.sample help text:

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)



ANSWER 2

Score 52


One easy way to select random items is to shuffle then slice.

import random
a = [1,2,3,4,5,6,7,8,9]
random.shuffle(a)
print a[:4] # prints 4 random variables



ANSWER 3

Score 47


I think random.choice() is a better option.

import numpy as np

mylist = [13,23,14,52,6,23]

np.random.choice(mylist, 3, replace=False)

the function returns an array of 3 randomly chosen values from the list




ANSWER 4

Score 3


  1. we have 3 samples ('orange','mango','apple'). Created series, should contain 7 elements & randomly selected from list.

    random.choice
    import random
    
    import numpy as np
    
    fruits = ['orange','mango','apple']
    
    np.random.choice(fruits, 7, replace=True)
    

    Output

    array(['orange', 'mango', 'apple', 'orange', 'orange', 'mango', 'apple'],
          dtype='<U6')
    
  2. Random selection from list (less than 3 values)

    random.sample
    import random
    
    random.sample(fruits, 3)