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Python - Set Functions - add, clear, difference, discard, intersection, checks, union, update

🐍 Advanced Sets

Let's create a blank set and learn by example.
Input
s = Set()

Add Elements to Set

Input
s.add(1)
s.add(2)
s 
Output
{1, 2}
This adds new elements to our existing set.

Clear

Input
s.clear()
s 
Output
set()
This empties the set. It deletes all elements.

Copy

Input
s = {1,2,3}
sc = s.copy()
print(s,sc)
Output
{1, 3, 4} {1, 2, 3}
This copies elements from one set to another.

Difference

Syntax
set1.difference(set2)
Input
s.add(4)
s.difference(sc)
Output
{4}
This returns elements that are not common in the two sets.

Difference Update

Syntax
set1.difference_update(set2)
Input
s1 = {1,2,3}
s2 = {1,4,5}
s1.difference_update(s2)
s1
Output
{2, 3}
This updates set1 to the difference between set1 and set2.

Discard

Syntax
set.discard(element)
Input
s = {1,2,3,4}
s.discard(2)
s
Output
{1, 3, 4}
This deletes an element from the set, if that element exists in the set.

Intersection

Syntax
set1.intersection(set2)
Input
s1 = {1,2,3}
s2 = {2,3,4}
s1.intersection(s2)
Output
{2, 3}
It returns the elements that are common in the two sets. It does NOT update any of the two sets.

Intersection Update

Syntax
set1.intersection_update(set2)
Input
s1 = {1,2,3}
s2 = {2,3,4}
s1.intersection(s2)
s1
Output
{2, 3}
It updates set1 with common elements between the two sets.

Is Disjoint?

Syntax
set1.isdisjoint(set2)
Input
s1 = {1,2,3}
s2 = {2,3,4}
s1.isdisjoint(s2)
Output
False
Input
s1 = {1,2,3}
s3 = {4,5,6}
s1.isdisjoint(s3)
Output
True
It returns True or False. Returns True if both sets are unique to each other, i.e. no common element in the two sets, else it returns false.

Is Subset?

Syntax
set1.issubset(set2)
Input
s1 = {1,2}
s2 = {1,2,3}
s1.issubset(s2)
Output
True
Input
s2.issubset(s1)
Output
False
It returns True or False. Returns True if set1 is subset of set2, else it returns false.

Is Superset?

Syntax
set1.issuperset(set2)
Input
s1 = {1,2,3}
s2 = {1,2}
s1.issuperset(s2)
Output
True
Input
s2.issuperset(s1)
Output
False
It returns True or False. Returns True if set1 is superset of set2, else it returns false.

Symmetric Difference?

Syntax
set1.symmetric_difference(set2)
Input
s1 = {1,2,3}
s2 = {1,2,4}
s1.symmetric_difference(s2)
Output
{3, 4}
It returns a set. A set of all the elements that are not common is returned.

Union?

Syntax
set1.union(set2)
Input
s1 = {1,2,3}
s2 = {1,2,4}
s1.union(s2)
Output
{1, 2, 3, 4}
It returns a set. A set of all the elements in both the sets, but just one occurrence of each element, is returned. Note that the returned set is not saved in set1 or set2.

Update?

Syntax
set1.update(set2)
Input
s1 = {1,2,3}
s2 = {1,2,4}
s1.update(s2)
s1
Output
{1, 2, 3, 4}
It saves a set in set1. A set of all the elements in both the sets, but just one occurrence of each element, is returned. This is similar to union, just that in this it updates set1 with the new set created.

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