How to Use Random Module in Python: Simple Guide

Use the random module in Python by first importing it with import random. Then, call functions like random.randint() for random integers, random.choice() to pick a random item from a list, or random.shuffle() to reorder a list randomly.

Syntax

First, import the random module. Then use its functions like:

• random.randint(a, b): returns a random integer between a and b inclusive.
• random.choice(sequence): picks a random element from a sequence like a list.
• random.shuffle(list): shuffles the list in place randomly.

python

import random

# Get a random integer between 1 and 10
num = random.randint(1, 10)

# Pick a random item from a list
item = random.choice(['apple', 'banana', 'cherry'])

# Shuffle a list
items = [1, 2, 3, 4, 5]
random.shuffle(items)

Example

This example shows how to generate a random number, pick a random fruit, and shuffle a list of numbers.

python

import random

# Random integer between 1 and 100
random_number = random.randint(1, 100)
print(f"Random number: {random_number}")

# Random choice from a list
fruits = ['apple', 'banana', 'cherry', 'date']
random_fruit = random.choice(fruits)
print(f"Random fruit: {random_fruit}")

# Shuffle a list
numbers = [10, 20, 30, 40, 50]
random.shuffle(numbers)
print(f"Shuffled numbers: {numbers}")

Output

Random number: 42
Random fruit: banana
Shuffled numbers: [40, 10, 50, 20, 30]

Common Pitfalls

One common mistake is forgetting to import the random module before using its functions. Another is expecting random.shuffle() to return a new list; it changes the list in place and returns None. Also, using random.randint(a, b) includes both a and b, so be careful with the range.

python

import random

# Wrong: forgetting import
# num = randint(1, 5)  # NameError: name 'randint' is not defined

# Wrong: expecting shuffle to return a list
numbers = [1, 2, 3]
shuffled = random.shuffle(numbers)
print(shuffled)  # Prints None
print(numbers)   # List is shuffled

# Right way:
random.shuffle(numbers)
print(numbers)

Output

None
[3, 1, 2]
[3, 1, 2]

Quick Reference

Function	Description	Example
random.randint(a, b)	Returns random integer between a and b inclusive	random.randint(1, 10)
random.choice(seq)	Returns random element from sequence	random.choice(['a', 'b', 'c'])
random.shuffle(list)	Shuffles list in place	random.shuffle(my_list)
random.random()	Returns random float between 0.0 and 1.0	random.random()

Key Takeaways

Always import the random module before using its functions.

Use random.randint(a, b) to get a random integer between a and b inclusive.

random.choice(sequence) picks a random item from any sequence like a list or string.

random.shuffle(list) changes the list order in place and returns None.

Check function behavior carefully to avoid common mistakes like expecting return values from shuffle.