Python Set

Python set

Created By: chatGPT

Sets in Python are a built-in data structure that allows you to store unique values. They are useful when you need to keep collections of items without duplicates. A set is unordered, meaning the items do not maintain a specific order. Sets can be created using curly braces {} or the set() constructor.

my_set = {1, 2, 3, 4, 5}

# Creating a set with the set() constructor
my_set2 = set([1, 2, 3, 4, 5])

You can perform various operations on sets, such as union, intersection, and difference. These operations can be performed using methods or operators.

set_a = {1, 2, 3}
set_b = {3, 4, 5}

# Union
union_set = set_a | set_b  # {1, 2, 3, 4, 5}

# Intersection
intersection_set = set_a & set_b  # {3}

# Difference
difference_set = set_a - set_b  # {1, 2}

You can also add or remove elements from a set using specific methods. Use add() to add a single element and update() to add multiple elements. To remove elements, use remove() or discard().

my_set.add(6)  # Add a single element
my_set.update([7, 8])  # Add multiple elements

my_set.remove(4)  # Removes 4, raises KeyError if not found
my_set.discard(4)  # Removes 4 but does not raise an error if not found

You can also check membership in a set using the in operator, which is an efficient way to check if an item exists in a set.

if 3 in my_set:
    print('3 is in the set!')

if 10 not in my_set:
    print('10 is not in the set!')

Sets also support frozen sets, which are immutable versions of regular sets. Once created, frozen sets cannot be modified.

frozen_set = frozenset([1, 2, 3])

# Immutable, following operations will raise error:
# frozen_set.add(4)  # AttributeError