random.random() / random.randint() / random.choice()

import random

# Returns a random floating-point number in the range [0.0, 1.0).
random.random()

# Returns a random integer between a and b (inclusive).
random.randint(a, b)

# Returns a random floating-point number between a and b.
random.uniform(a, b)

# Returns a randomly chosen element from a sequence.
random.choice(sequence)

# Returns a list of k unique elements chosen from the sequence.
random.sample(sequence, k)

# Shuffles the list in place.
random.shuffle(list)

random_basic.py

import random

print(random.random())

dice = random.randint(1, 6)
print(f"Dice: {dice}")

temp = random.uniform(20.0, 30.0)
print(f"Temperature: {temp:.1f}°C")

Running the code produces the following output:

python3 random_basic.py
0.8444218515250481
Dice: 1
Temperature: 27.0°C

random_choice_sample.py

import random

fighters = ["Iori Yagami", "Kyo Kusanagi", "Terry Bogard", "Mai Shiranui", "Chris"]
picked = random.choice(fighters)
print(f"Picked fighter: {picked}")

winners = random.sample(fighters, k=3)
print(f"TOP3: {winners}")

kof_bgm = ["Arashi no Saxophone 2", "Wild Party", "Terry 115", "Mai", "Resurrection"]
print(f"Tonight's BGM: {random.choice(kof_bgm)}")

Running the code produces the following output:

python3 random_choice_sample.py
Picked fighter: Kyo Kusanagi
TOP3: ['Iori Yagami', 'Terry Bogard', 'Mai Shiranui']
Tonight's BGM: Arashi no Saxophone 2

random_shuffle_seed.py

import random

cards = list(range(1, 14))
random.shuffle(cards)
print(cards)

random.seed(42)
print(random.randint(1, 100))

Running the code produces the following output:

python3 random_shuffle_seed.py
[10, 4, 5, 7, 3, 9, 6, 8, 2, 11, 1, 12, 13]
82

Common Mistake 1: Using the return value of shuffle()

random.shuffle() shuffles the list in place and returns None. Assigning the return value to a variable has no effect.

import random

fighters = ["Iori Yagami", "Kyo Kusanagi", "Terry Bogard"]
shuffled = random.shuffle(fighters)
print(shuffled)

The same logic can also be written as:

import random

fighters = ["Iori Yagami", "Kyo Kusanagi", "Terry Bogard"]
random.shuffle(fighters)
print(fighters)

Common Mistake 2: Using random for security-sensitive purposes

The random module is not suitable for use cases that require cryptographically secure random values, such as generating passwords or tokens. The secrets module is a safer choice for such purposes.

import random
import string

chars = string.ascii_letters + string.digits
password = "".join(random.choice(chars) for _ in range(16))
print(password)

The same logic can also be written as:

import secrets
import string

chars = string.ascii_letters + string.digits
password = "".join(secrets.choice(chars) for _ in range(16))
print(password)

Python's random module uses the Mersenne Twister algorithm to generate high-quality pseudo-random numbers. It is suitable for a wide range of applications such as games, simulations, and test data generation.

random.shuffle() modifies the list in place, so it returns None. If you want to keep the original list unchanged, make a copy before shuffling.

There are cases where the random module is not a good fit for security-sensitive purposes. When you need cryptographically secure random values — such as for passwords or tokens — the secrets module (e.g., secrets.token_hex() or secrets.choice()) is a safer option.