frozenset() in Python

The frozenset() is an inbuilt function is Python which takes an iterable object as input and makes them immutable. Simply it freezes the iterable objects and makes them unchangeable.

In Python, frozenset is same as set except its elements are immutable. This function takes input as any iterable object and converts them into immutable object. The order of element is not guaranteed to be preserved.

Syntax : frozenset(iterable_object_name)



Parameter : This function accepts iterable object as input parameter.

Return Type: This function return an equivalent frozenset object.

Below examples explains it clearly.

Example #1:

If no parameters are passed to frozenset() function then it returns a empty frozenset type object.

filter_none

edit
close

play_arrow

link
brightness_4
code

# Python program to understand frozenset() function
  
# tuple of numbers
nu = (1, 2, 3, 4, 5, 6, 7, 8, 9)
  
# converting tuple to frozenset
fnum = frozenset(nu)
  
# printing details
print("frozenset Object is : ", fnum)

chevron_right


Output:

frozenset Object is :  frozenset({1, 2, 3, 4, 5, 6, 7, 8, 9})

 

Example #2: Uses of frozenset().

Since frozenset object are immutable they are mainly used as key in dictionary or elements of other sets. Below example explains it clearly.

filter_none

edit
close

play_arrow

link
brightness_4
code

# Python program to understand use
# of frozenset function
  
# creating a dictionary 
Student = {"name": "Ankit", "age": 21, "sex": "Male"
           "college": "MNNIT Allahabad", "address": "Allahabad"}
  
# making keys of dictionary as frozenset
key = frozenset(Student)
  
# printing keys details
print('The frozen set is:', key)

chevron_right


Output:

The frozen set is: frozenset({'sex', 'age', 'address', 'name', 'college'})

 
Example #3: Warning

If by mistake we want to change the frozenset object then it throws an error “‘frozenset’ object does not support item assignment“.

filter_none

edit
close

play_arrow

link
brightness_4
code

# Python program to understand
# use of frozenset function
  
# creating a list 
favourite_subject = ["OS", "DBMS", "Algo"]
  
# making it frozenset type
f_subject = frozenset(favourite_subject)
  
# below line will generate error
  
f_subject[1] = "Networking"

chevron_right


Output:

Traceback (most recent call last):
  File "/home/0fbd773df8aa631590ed0f3f865c1437.py", line 12, in 
    f_subject[1] = "Networking"
TypeError: 'frozenset' object does not support item assignment


My Personal Notes arrow_drop_up

All powers are within you You can do anything and everything Believe in that

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.