set

• sets represent unordered collections of unique elements
• Eliminate duplicate entries: Sets automatically remove duplicates, ensuring each element appears only once.
• Check for membership: Quickly determine if an element exists in the set using the in operator.
• Perform set operations: Sets support mathematical operations like union (combining elements), intersection (finding common elements), and difference (elements in one set but not the other).
• Set can be created using curly braces {} or using set() function
• Key Characteristics
  • Unordered: Elements in a set don't have a specific order, and iterating over a set won't guarantee the order in which you get the elements.
  • Unchangeable: Sets themselves are immutable, meaning you cannot modify the elements after creation. However, you can create a new set with changes.
• Accessing Elements
  • Since sets are unordered, you cannot access elements by index. However, you can check for membership using the in operator
• Adding or Removing Elements
  • Sets are mutable in the sense that you can add or remove elements, but you cannot modify existing elements
    • add(element): Add a new, unique element to the set.
    • remove(element): Remove the first occurrence of an element (error if not found).
    • discard(element): Similar to remove, but ignores the error if the element is not found.
    • pop(): Removes and returns an arbitrary element from the set (raises a KeyError if the set is empty).
    • update(iterable): Update the set by adding elements from another iterable (like a list or another set).
• Set Operations
  • union |: Combines elements from both sets, excluding duplicates.
  • intersection &: Returns elements that are common to both sets.
  • difference -: Returns elements in the first set that are not in the second set.
  • symmetric_difference ^: Returns elements that are in either set but not in both.
• Common Set Methods
  • len(set): Returns the number of elements in the set.
  • isdisjoint(other_set): Checks if two sets have no common elements (are disjoint).
  • issubset(other_set): Checks if all elements in the first set are also in the other set.
  • issuperset(other_set): Checks if the first set contains all elements of the other set and may have additional elements.
• When to Use Sets
  • Use sets when you need to store unique elements and perform membership checks efficiently.
  • They are useful for deduplicating data, performing set operations, and working with collections where order doesn't matter.
• Key Points
  • Sets are unordered collections with unique elements.
  • They are useful for eliminating duplicates, checking membership, and performing set operations.
  • Sets are mutable in the sense that you can add or remove elements, but the elements themselves are immutable.
  • Understand the different set methods and operators to effectively work with sets in your Python programs

fruits = {"apple", "banana", "cherry", "apple"}  # Duplicates will be removed

numbers_list = [1, 2, 2, 3, 4]
numbers_set = set(numbers_list)  # Converts a list with duplicates to a set (duplicates removed)

if "mango" in fruits:
    print("Mango is in the set.")

fruits = {"apple", "banana", "cherry", "apple"} # Duplicates will be removed numbers_list = [1, 2, 2, 3, 4] numbers_set = set(numbers_list) # Converts a list with duplicates to a set (duplicates removed) if "mango" in fruits: print("Mango is in the set.")