Introduction to the Python Random Library

Introduction

Python has a built-in random library that provides various functions for performing stochastic operations. In this chapter, we'll explore some of the most commonly used functions in the random library, including generating random numbers, making random choices, and shuffling sequences.

Generating Random Numbers

Several functions are available to generate random numbers, including random, uniform, randint, and randrange. Here's an example of using these functions to generate random numbers representing the roll of a die and the toss of a coin:

import random

# Generate a random integer between two values
min_die = 1
max_die = 6
die_roll = random.randint(a=min_die, b=max_die)
print(f"Die roll: {die_roll}")

Output:
Die roll: 4

# Generate a random choice from a sequence
coin_toss = random.choice(seq=["heads", "tails"])
print(f"Coin toss: {coin_toss}")

Output:
Coin toss: tails

Making Random Choices

The choice and choices functions are available to make random selections from a sequence. Here's an example of using these functions to randomly select a card from a deck of cards:

import random

cards = ["Ace", "2", "3", "4", "5", "6", "7", "8", "9", "10", "Jack", "Queen", "King"]

# Make a random choice from a sequence
card = random.choice(seq=cards)
print(f"Randomly selected card: {card}")

Output:
Randomly selected card: 7

# Make multiple random choices from a sequence
num_choices = 5
cards = random.choices(population=cards, k=num_choices)
print(f"Randomly selected cards: {cards}")

Output:
Randomly selected cards: ['Queen', '3', 'King', '9', '8']

Shuffling Sequences

The shuffle function is available to shuffle a sequence in place randomly. Here's an example of using the shuffle function to randomly shuffle a list of cards:

import random

cards = ["Ace", "2", "3", "4", "5", "6", "7", "8", "9", "10", "Jack", "Queen", "King"]

# Shuffle a sequence in place
random.shuffle(x=cards)
print(f"Shuffled cards: {cards}")

Output:
Shuffled cards: ['3', 'Queen', '8', '2', 'King', 'Jack', 'Ace', '9', '6', '7', '10', '5', '4']

Conclusion

Whether you're simulating a game of chance or generating random data for a machine-learning model, the random library is an essential tool for any Python programmer.