CODEWITHSUNDEEP
pythonrandom
emmagras
emmagras

Reputation: 1407

Returning N random items from smaller original list

I'm surprised I haven't found a way to do this without a loop, since it seems like a pretty standard problem.
Working in python, I have colors = ["red","green","blue"] and I'd like to put these elements into a list of length N in a random order. Right now I'm using:

import random
colors = ["red","green","blue"]
otherList = []

for i in range (10):  # N=10 
    otherList.append(random.choice(colors))

This returns: otherList = ["red","green","green","green","blue","green","red","green","green","blue"], which is exactly what I want. I'm just looking for a more idiomatic way of doing this? Any ideas? It looked like random.sample might have been the answer, but I didn't see anything in the documentation that fit exactly my needs.

Upvotes: 3

Views: 143

Answers (2)

mgilson
mgilson

Reputation: 309929

You can use a list comprehension:

[random.choice(colors) for i in range(10)] #xrange for python2 compatability

Or random.sample() through some gymnastics:

nrandom = 10
random.sample( colors*(nrandom//len(colors)+1), nrandom )

Although I don't think that is better than the list-comprehension ...

Upvotes: 6

Ashwini Chaudhary
Ashwini Chaudhary

Reputation: 250951

>>> import random
>>> colors = ["red","green","blue"]
>>> [random.choice(colors) for i in range(10)]
['green', 'green', 'blue', 'red', 'red', 'red', 'green', 'red', 'green', 'blue']

Upvotes: 2

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