Python Random Module

Python Random module generates random numbers in Python. These are pseudo-random numbers means they are not truly random.

This module can be used to perform random actions such as generating random numbers, printing random a value for a list or string, etc. It is an in-built function in Python.

Applications of Python Random Module

Here are some real-life uses of Python’s random module:

1. Creating dice rolls or card draws in games.
2. Simulating random events in traffic or stock market models.
3. Selecting random samples from survey data.
4. Splitting datasets into training and testing sets in machine learning.
5. Generating random passwords or session tokens for security.
6. Creating fake test data for software testing.
7. Stress testing apps with random inputs.

List of all the functions  Python Random Module

There are different random functions in the Random Module of Python. Look at the table below to learn more about these functions:

Random Module in Python Examples

Let’s discuss some common operations performed by Random module in Python.

Printing a random value from a list in Python.

This code uses the random module to select a random element from the list q using the random.choice() function. It prints a random element from the list, demonstrating how to pick a random item from a sequence in Python.

import random
a = [1, 2, 3, 4, 5, 6]
print(random.choice(a))

3

Creating random numbers with Python seed() in Python.

Random numbers depend on the seeding value. For example, if the seeding value is 5 then the output of the below program will always be the same. Therefore, it must not be used for encryption.

The code sets the random number generator’s seed to 5 using random.seed(5). It then prints two random floating-point numbers between 0 and 1 using random.random(). The seed makes these numbers the same every time you run the code with a seed of 5.

import random
random.seed(5)
print(random.random())
print(random.random())

0.6229016948897019
0.7417869892607294

Generate Random Numbers in Python

random.randint() method is used to generate random integers between the given range.

Syntax: randint(start, end)

Example: Creating random integers

It first generates a random integer between 5 and 15 (inclusive) and then between -10 and -2 (inclusive). The generated integers are printed with appropriate formatting.

import random
r1 = random.randint(5, 15)
print("Random number between 5 and 15 is % s" % (r1))

r2 = random.randint(-10, -2)
print("Random number between -10 and -2 is % d" % (r2))

Random number between 5 and 15 is 10
Random number between -10 and -2 is -2

Generate Random Float numbers in Python

A random.random() method is used to generate random floats between 0.0 to 1.

Syntax: random.random()

Example:

In this code, we are using the random function from the ‘random’ module in Python. It prints a random floating-point number between 0 and 1 when you call random().

from random import random
print(random())

0.8443722499369146

Randomly Select Elements from a List in Python

Random sampling from a list in Python (random.choice, and sample)

Example 1:  Python random.choice() function is used to return a random item from a list, tuple, or string.

import random

a = [1, 2, 3, 4, 5, 6]
print(random.choice(a))

s = "geeks"
print(random.choice(a))

tup = (1, 2, 3, 4, 5)
print(random.choice(tup))

4
k
5

Example 2:  Python random.sample() function is used to return a random item from a list, tuple, or string.

Syntax: random.sample(sequence, length)

It selects three random elements without replacement from a list, a tuple, and a string, demonstrating its versatility in generating distinct random samples. With each execution, the selected elements will differ, providing random subsets from the input data structures.

from random import sample

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

b = (4, 5, 6, 7, 8)
print(sample(b,3))

c = "45678"
print(sample(c,3))

[4, 2, 3]
[4, 7, 8]
['6', '4', '8']

Shuffle List in Python

A random.shuffle() method is used to shuffle a sequence (list). Shuffling means changing the position of the elements of the sequence. Here, the shuffling operation is inplace.

Syntax: random.shuffle(sequence, function)

Example: Shuffling a List

The code randomly reorders the elements of list a twice using random.shuffle() and prints the results each time.

import random
a = [1, 2, 3, 4, 5]

random.shuffle(a)
print("After shuffle : ")
print(a)

random.shuffle(a)
print("\nSecond shuffle : ")
print(a)

After shuffle : 
[1, 4, 2, 5, 3]

Second shuffle : 
[1, 4, 3, 5, 2]

In this article we discussed about Python Random module, and also saw some examples of functions in random module in Python. Random module in Python is very important and contains very useful functions.

Hope this helps you in using Python Random module functions.

More on Python Modules:

• Python sys Module
• Python datetime Module
• Built-in Modules in Python
• External Modules in Python