random.sample() function - Python

sample() is an built-in function of random module in Python that returns a particular length list of items chosen from the sequence i.e. list, tuple, string or set. Used for random sampling without replacement. Example:

from random import sample

a = [1, 2, 3, 4, 5] 
print(sample(a,3))

[2, 5, 1]

Explanation: This code uses the sample() method to randomly select 3 unique elements from the list a = [1, 2, 3, 4, 5]. The selected elements are printed as a new list.

Syntax

random.sample(sequence, k)

Parameters:

• sequence: Can be a list, tuple, string, or set.
• k: An Integer value, it specify the length of a sample.

Returns: k length new list of elements chosen from the sequence.

Examples of random.sample() function

Example 1: Basic use of sample() function

The code demonstrates how to use random.sample() with different types of sequences:

import random

a = [1, 2, 3, 4, 5, 6] 
print("With list:", random.sample(a, 3))

s = "GeeksforGeeks"
print("With string:", random.sample(s, 4))

t = ("ankit", "geeks", "computer", "science", "portal", "scientist", "btech")
print("With tuple:", random.sample(t, 4))

b = {"a", "b", "c", "d", "e"}
print("With set:", random.sample(list(b), 3))

With list: [3, 4, 5]
With string: ['r', 'k', 'f', 'e']
With tuple: ['btech', 'scientist', 'portal', 'science']
With set: ['b', 'a', 'e']

Explanation:

• List: It randomly selects 3 elements from the list a.
• String: It randomly selects 4 characters from the string s.
• Tuple: It randomly selects 4 elements from the tuple t.
• Set: Since random.sample() does not directly work with sets, the set b is converted into a list, and 3 random elements are selected.

Example 2: Sampling More Elements Than Available in List

This code demonstrates the behavior of random.sample() when we try to sample more elements than are present in the list, which will result in a ValueError.

import random

a = [1, 2, 3, 4] 
print(random.sample(a, 5)) 

Output:

Traceback (most recent call last):
  File "/home/guest/sandbox/Solution.py", line 4, in <module>
    print(random.sample(a, 5))
          ~~~~~~~~~~~~~^^^^^^
  File "/usr/local/lib/python3.13/random.py", line 434, in sample
    raise ValueError("Sample larger than population or is negative")
ValueError: Sample larger than population or is negative