Get a random sample with replacement

Question

I have this list:

colors = ["R", "G", "B", "Y"]

and I want to get 4 random letters from it, but including repetition.

Running this will only give me 4 unique letters, but never any repeating letters:

print(random.sample(colors,4))

How do I get a list of 4 colors, with repeating letters possible?

Related: Without replacement(keep order: https://stackoverflow.com/questions/6482889/get-random-sample-from-list-while-maintaining-ordering-of-items ; without keep order (normal): https://stackoverflow.com/questions/22741319/what-does-random-sample-method-in-python-do, weighted: https://stackoverflow.com/questions/43549515/weighted-random-sample-without-replacement-in-python) — user202729, Dec 30 '21 at 03:51

score 80 · Answer 1 · answered Apr 27 '17 at 05:37

80

In Python 3.6, the new random.choices() function will address the problem directly:

>>> from random import choices
>>> colors = ["R", "G", "B", "Y"]
>>> choices(colors, k=4)
['G', 'R', 'G', 'Y']

answered Apr 27 '17 at 05:37

Raymond Hettinger

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score 23 · Answer 2 · edited Nov 13 '17 at 14:56

23

Try numpy.random.choice (documentation numpy-v1.13):

import numpy as np
n = 10 #size of the sample you want
print(np.random.choice(colors,n))

edited Nov 13 '17 at 14:56

normanius

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answered Apr 07 '17 at 15:31

Priyank

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trincot · Answer 3 · 2017-04-07T15:43:21.687

23

With random.choice:

print([random.choice(colors) for _ in colors])

If the number of values you need does not correspond to the number of values in the list, then use range:

print([random.choice(colors) for _ in range(7)])

From Python 3.6 onwards you can also use random.choices (plural) and specify the number of values you need as the k argument.

edited Apr 07 '17 at 15:43

answered Apr 07 '17 at 15:33

trincot

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score 1 · Answer 4 · answered Apr 07 '17 at 16:23

This code will produce the results you require. I have added comments to each line to help you and other users follow the process. Please feel free to ask any questions.

import random

colours = ["R", "G", "B", "Y"]  # The list of colours to choose from
output_Colours = []             # A empty list to append results to
Number_Of_Letters = 4           # Allows the code to easily be updated

for i in range(Number_Of_Letters):  # A loop to repeat the generation of colour
    output_Colours.append(random.sample(colours,1)) # append and generate a colour from the list

print (output_Colours)

Excellent! I cried. Elementary, said he. – mccurcio Oct 21 '22 at 21:30 — mccurcio, Oct 21 '22 at 21:30

Get a random sample with replacement

4 Answers4

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