List Mutability and Comparison with Sets

CS 5001/5002 - Strings, Sequences & Sets

Code

#!/usr/bin/env python3
"""
Filename: list_mutability_sets.py
Description: List Mutability and Comparison with Sets
CS 5001/5002 - Strings, Sequences & Sets

This script demonstrates the mutable nature of lists and compares their
behavior with sets, particularly regarding duplicates and ordering.
"""

def main():
    # Lists are mutable sequences
    data = [13, 15, -4, 31, 5, 6, 19]
    print(f"Original list: {data}")

    # We can modify individual elements
    data[0] = 42
    print(f"After modifying index 0: {data}")

    # Lists preserve order and allow duplicates
    numbers = [3, 1, 4, 1, 5, 9, 2, 6, 5]
    print(f"List with duplicates: {numbers}")
    print(f"Length: {len(numbers)}")

    # Convert to set to remove duplicates
    unique_numbers = set(numbers)
    print(f"As set (unique): {unique_numbers}")
    print(f"Unique count: {len(unique_numbers)}")

    # Convert back to list (order may change)
    back_to_list = list(unique_numbers)
    print(f"Back to list: {back_to_list}")

    # Sorted version for consistent ordering
    sorted_unique = sorted(unique_numbers)
    print(f"Sorted unique: {sorted_unique}")

if __name__ == "__main__":
    main()

How to Use

1. Copy the code above
2. Save it as a .py file (e.g., list_mutability_sets.py)
3. Run it with: python list_mutability_sets.py

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Part of CS 5001/5002 - Strings, Sequences & Sets materials