CODEWITHSUNDEEP
pythonrandom
randme
randme

Reputation: 41

How can you select a random element from a list, and have it be removed?

Let's say I have a list of colours, colours = ['red', 'blue', 'green', 'purple'].
I then wish to call this python function that I hope exists, random_object = random_choice(colours). Now, if random_object holds 'blue', I hope colours = ['red', 'green', 'purple'].

Does such a function exist in python?

Upvotes: 3

Views: 9549

Answers (2)

Russell Borogove
Russell Borogove

Reputation: 19037

Firstly, if you want it removed because you want to do this again and again, you might want to use random.shuffle() in the random module.

random.choice() picks one, but does not remove it.

Otherwise, try:

import random

# this will choose one and remove it
def choose_and_remove( items ):
    # pick an item index
    if items:
        index = random.randrange( len(items) )
        return items.pop(index)
    # nothing left!
    return None

Upvotes: 8

flow
flow

Reputation: 3652

one way:

from random import shuffle

def walk_random_colors( colors ):
  # optionally make a copy first:
  # colors = colors[:] 
  shuffle( colors )
  while colors:
    yield colors.pop()

colors = [ ... whatever ... ]
for color in walk_random_colors( colors ):
  print( color )

Upvotes: 7

Related Questions