What is a Frozen Set ?
                  A frozen set is similar to the normal set but here it is immutable .
                  In Frozen Set, one cannot add element, remove element or modify element. 

Because of immutability, frozen sets are:

  • hashable
  • secure
  • safe to use as dictionary keys
  • efficient in memory

Creation :

Python 
numbers = frozenset({1, 2, 3, 4}) fs = frozenset([10, 20, 30]) print(numbers) print(fs) #output frozenset({1, 2, 3, 4}) frozenset({10, 20, 30})


Features :
  • unordered
  • unindexed
  • immutable
  • duplicate free

Valid Operations :

union( ) :

Python 
a = frozenset({1, 2}) b = frozenset({2, 3}) print(a.union(b)) #output frozenset({1, 2, 3})


intersection( ) :

Python 
x = frozenset({1, 2, 3}) y = frozenset({2, 3, 4}) print(x.intersection(y)) #output frozenset({2, 3})


difference( ) :

Python 
x = frozenset({1, 2, 3}) y = frozenset({2, 3, 4}) print(x.difference(y)) #output frozenset({1})