Python Random Library Guide

The Python random module provides tools for generating random numbers, selecting random elements, and more. This guide covers the most commonly used functions.

For more information, check the Python random documentation.

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1. random()

• Description: Generates a random floating-point number between 0.0 (inclusive) and 1.0 (exclusive).

• Example:

  import random
  print(random.random())  # Outputs a number like 0.45238
  

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2. randint(a, b)

• Description: Returns a random integer between a and b (both inclusive).
• Example:

  import random
  print(random.randint(1, 10))  # Outputs an integer between 1 and 10
  

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3. choice(seq)

• Description: Returns a random element from a non-empty sequence (e.g., list, string, tuple).
• Example:

  import random
  items = ["apple", "banana", "cherry"]
  print(random.choice(items))  # Outputs a random item from the list
  

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4. choices(seq, k)

• Description: Returns a list of k random elements from the sequence, with replacement.
• Example:

  import random
  items = ["apple", "banana", "cherry"]
  print(random.choices(items, k=3))  # Outputs something like ['banana', 'apple', 'cherry']
  

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5. shuffle(seq)

• Description: Shuffles a sequence in place (mutates the original sequence).
• Example:

  import random
  items = ["apple", "banana", "cherry"]
  random.shuffle(items)
  print(items)  # Outputs a shuffled version of the list
  

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6. sample(seq, k)

• Description: Returns a list of k unique elements randomly chosen from the sequence, without replacement.
• Example:

  import random
  items = ["apple", "banana", "cherry", "date"]
  print(random.sample(items, k=2))  # Outputs something like ['cherry', 'banana']
  

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7. uniform(a, b)

• Description: Returns a random floating-point number between a and b.
• Example:

  import random
  print(random.uniform(1.5, 3.5))  # Outputs a float like 2.473
  

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8. randrange(start, stop, step)

• Description: Returns a randomly selected element from the range [start, stop) with the given step.
• Example:

  import random
  print(random.randrange(1, 10, 2))  # Outputs a random odd number between 1 and 9
  

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9. seed(value)

• Description: Initializes the random number generator to make results reproducible.
• Example:

  import random
  random.seed(42)
  print(random.random())  # Same output every time the script is run
  

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10. Generating Random Booleans

• Description: You can simulate random boolean values using choice.
• Example:

  import random
  print(random.choice([True, False]))  # Outputs True or False randomly
  

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