[SOLVED] How does the random.choices function work in Python?

Question

And in which ways does it differ with random.sample and random.choice?

Answer 1

random.choices(list, weights=list, cum_weights=list, k=int) returns k elements from list with weighted probabilites.

Example:

from random import choices

dice = [*range(1, 7)] # [1, 2, 3, 4, 5, 6]

weights = [1 for i in range(6)] # [1, 1, 1, 1, 1, 1], equal weights => same probability for every number

print(choices(dice, weights=weights, k=10)) # [2, 2, 3, 2, 4, 4, 5, 6, 4, 3]

weights = [0, 0, 0, 1, 1, 5] # first three elements have a weight of 0 and will be excluded. 6 has the heighest weight/probability

print(choices(dice, weights=weights, k=10)) # [6, 5, 6, 5, 5, 6, 6, 4, 6, 6]

cum_weights means that the probablities are added up instead of listed individually:

weights = [1, 1, 1, 1, 1, 1] # cumulated weights don't change = there's a 100% chance for a 1

print(choices(dice, cum_weights=weights, k=10)) # [1, 1, 1, 1, 1, 1, 1, 1, 1, 1]

Answer 2

random.choice() selects a random object from the list.

>>> random.choice([1,2,3,4])
2

random.sample() allows you to randomly select more than 1 object, and return them as a list.

>>> random.sample([1,2,3,4], 2)
[1,3]

Answer 3

Guess I'm really blind. Sorry about that. :D

Anyway, I'm sure you've also read the docs?

https://docs.python.org/3/library/random.html

According to what is defined, it appears that random.choices work like random.sample but allows you to specify weights to each element.

Answer 4

Anna Thank you very much!
Thank you too, Hatsy Rei!

Answer 5

Hatsy Rei thanks, but in fact I already knew about these two. My question is about the random.choices() function and its differences with random.sample() and random.choice().