Random generator that removes items from a list after picking

user_8510149 0
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I have a list with 48 items. I want to randomly pick out 3 of those items, then remove those three items from the list. After that, randomly pick 3 new items. I wish to loop this 16 times until all the items are removed.

I've tried a for loop. But I can't figure out how to remove those specific items that was randomly selected from the list. I'm pretty new at both Python and programming. Help would be much appreciated.

list_ = ['Pink', 'Red', 'Green', 'Darkgreen', 'Blue', 'Skyblue'] * 8

loop_ = np.arange(0, 16)

for i in loop:
    print(random.sample(list_, 3))
random python
4 Answers

np.arange(1,16) is of 15 length, but you want to loop 16 times. Also, avoide using list.remove when there are duplicates in the list, even though probably it will not cause troubles in your specific problem. Finally, as said, avoid using 'list' as name as it's already used by Python. Here is my suggestion, working on indexes and using list.pop(0) method:

l = ['Pink', 'Red', 'Green', 'Darkgreen', 'Blue', 'Skyblue'] * 8

for i in range(16):
    item = random.sample(range(len(l)), 3)
    for k in sorted(item, reverse=True):
        l.pop(k)

print(l)
#[]
user_82285580

You can use the list.remove() method:

import numpy as np
import random

list = ['Pink', 'Red', 'Green', 'Darkgreen', 'Blue', 'Skyblue'] * 8

loop = np.arange(1,16)

for i in loop:
    item = random.sample(list, 3)
    print(item)
    for i in item:
        list.remove(i)

Note that is it considered a bad practice to name variables the names already given to built-ins, such as list. It would be better to name your list something else, for example, colors:

import random

colors = ['Pink', 'Red', 'Green', 'Darkgreen', 'Blue', 'Skyblue'] * 8

for i in range(0, len(colors), 3):
    item = random.sample(colors, 3)
    print(item)
    for i in item:
        colors.remove(i)

UPDATE

As pointed out nicely by @dawg, the list.remove() method always removes items from the list closest to the start of the list, taking away the concept of randomness.

I realized that it would be more accurate to use indices instead of values, so use list.pop() instead of list.remove():

from random import randint

colors = ['Pink', 'Red', 'Green', 'Darkgreen', 'Blue', 'Skyblue'] * 8

while colors:
    lst = [colors.pop(randint(0, len(colors) - 1)) for _ in range(3)]
    print(lst)
user_135524700

you can also do the list.pop(index) method.

import random as rd
import numpy as np
lst = ['Pink', 'Red', 'Green', 'Darkgreen', 'Blue', 'Skyblue'] * 8
loop = np.arange(1,16)
for i in loop:
    for k in range(0,3):
        item = lst.pop(rd.choice(range(0,len(lst))))
        print(item)

.pop(index) method does two things. It returns the element at the given index of a list. It then removes that element from the list.

Inside of the .pop() function we have the following: a random choice of a number (which is the index) the choice is a list of numbers between 0 and the length of the list (exclusive).

user_81724890 
import random

my_list = [
    1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,
    18, 19, 20, 21, 22, 23, 24, 25,26, 27, 28, 29, 30, 31, 32,
    33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48
]

for i in range(16):
    removed_list = random.sample(my_list, 3)
    for item in removed_list:
        my_list.remove(item)
        
print(my_list)
user_148780090
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