What is Set?
Accessing a Set
5) Union of Sets  
Set methods
 Set is an unordered collection data type with no duplicate elements. (unique elements)
 Using curly braces {} or keyword set, we can create a set in Python.
Creating a Set
 In python, the set can be created using curly braces {} or keyword set.
 Ex: S = { 'y', 't', 'p', 'h', 'n', 'o'} or S = set('y', 't', 'p', 'h', 'n', 'o')
 Even if we pass duplicate elements while creating a set. It won't throw an error instead it removes the duplicate and returns the set with unique elements.
Set with a unique element without duplicates 
 Set can be iterated but it is unindexed. This means we can't perform index access since the set is unordered.
 Ex:
Set Iteration 
 Similarly, we can check whether an element present in the given set or not using 'in' keyword.
 Ex:
Accessing set Element using 'in' keyword 
Set Methods
1) Adding new element to the set  add()
2) Removing element from the set  remove() / discard() / pop()
remove()
1) Adding new element to the set  add()
 Using add() method, we can add an element to the given set. Since the set is unordered, there is no particular index to the newly added element.
add() method in set 
remove()
 Using remove() method, we can remove a particular element in the given set.
remove() method 
 If the element isn't present in the set, then it will throw an error like below.
Error is thrown by remove() method 
discard()
pop()
3) Adding more than one element to the set  update()
4) Clearing & deleting the set Clear(), del
 Discard method also removes the element from the set.
 But the difference between remove() and discard is, discard() method will not throw an error if the element not present in the set.
discard() method in set 
 We can also use pop() method to remove an element from the set but pop() method always removes the last element
 Since the set is unordered, so we will not know what element gets removed by pop()
 Removed item will be shown by the return value of pop()
pop() method 
 We can add multiple items to a set using the update() method
Adding multipleelement using update() method 
 To empties, a set, clear() method is used.
Clear() method 
 Del keyword used to delete the set completely
Del method 
 Union operation merges elements of two sets and creates a new set that contains all the distinct elements from both sets.
 In the below example, "Apple"(element) is present in both the sets. But when executed, the result has only one "Apple".
Union operation in Set 
6) Intersection of Sets  &
 Intersection operation creates a new set that contains a common element from both sets.
 In the below example, "Apple" is present both sets. When executed, the result contains only "Apple" which is common in both sets.
Intersection operation in Set 
7) Difference of Sets  ''
 Difference operation creates a new set that contains only the element from set 1 and none from set 2.
 In the below example, the difference operation was performed on two sets fruit1 and fruit2. When executed, the result contains only elements that are unique in the first set fruit1.
Difference of set operation 
 In Python, we have a set of builtin methods that you can use on Sets
Method

Description

add()

Adds
an element to the set

clear()

Removes all elements from the set

copy()

Returns
a copy of the set

difference()

Returns the difference of two or more sets as a new set

difference_update()

Removes
all elements of another set from this set

discard()

Removes an element from the set if it is a member. (Do nothing if the
element is not in set)

intersection()

Returns
the intersection of two sets as a new set

intersection_update()

Updates the set with the intersection of itself and another

isdisjoint()

Returns
True if two sets have a null intersection

issubset()

Returns True if another set contains this set

issuperset()

Returns
True if this set contains another set

pop()

Removes and returns an arbitrary set element. Raises KeyError if the
set is empty

remove()

Removes
an element from the set. If the element is not a member, raises a KeyError

symmetric_difference()

Returns the symmetric difference of two sets as a new set

symmetric_difference_update()

Updates
a set with the symmetric difference of itself and another

union()

Returns the union of sets in a new set

update()

Updates
the set with the union of itself and others

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