Python Method creates an immutable Set object from an iterable. It is a built-in Python function. As it is a set object, therefore, we cannot have duplicate values in the frozenset.
Example
In this example, we are creating a frozen set with the list in Python.
Python3
animals = frozenset(["cat", "dog", "lion"])print("cat" in animals)print("elephant" in animals) |
Output
True
False
Python frozenset() Syntax
Syntax : frozenset(iterable_object_name)
Parameter : iterable_object_name
- This function accepts iterable object as input parameter.
Return : Returns an equivalent frozenset object.
frozenset() in Python Examples
Working of Python frozenset()
In this example, we are showing how to create a frozen set in Python and we are showing that frozen set objects are immutable and can not be modified after the creation.
Python3
fruits = frozenset(["apple", "banana", "orange"])print(fruits)fruits.append("pink")print(fruits) |
Output
frozenset({'banana', 'orange', 'apple'})
Traceback (most recent call last):
File "C:\Users\ashub\OneDrive\Desktop\achal cahtgpt\temp.py", line 3, in <module>
fruits.append("pink")
AttributeError: 'frozenset' object has no attribute 'appen
Python frozenset for Tuple
If no parameters are passed to frozenset() function, then it returns an empty frozenset type object in Python.
Python3
# passing an empty tuplenu = ()# converting tuple to frozensetfnum = frozenset(nu)# printing empty frozenset objectprint("frozenset Object is : ", fnum) |
Output
frozenset Object is : frozenset()
Python frozenset for List
Here as a parameter a list is passed and now its frozen set object is returned.
Python3
l = ["Geeks", "for", "Geeks"] # converting list to frozensetfnum = frozenset(l) # printing empty frozenset objectprint("frozenset Object is : ", fnum) |
Output
frozenset Object is : frozenset({'Geeks', 'for'})
frozenset in Python for Dictionary
Since frozen set objects are immutable, they are mainly used as keys in dictionary or elements of other sets. The below example explains it clearly.
Python3
# creating a dictionaryStudent = {"name": "Ankit", "age": 21, "sex": "Male", "college": "MNNIT Allahabad", "address": "Allahabad"}# making keys of dictionary as frozensetkey = frozenset(Student)# printing dict keys as frozensetprint('The frozen set is:', key) |
Output
The frozen set is: frozenset({'address', 'name', 'age', 'sex', 'college'})
Exceptions while using the frozenset() method in Python
If by mistake we want to change the frozen set object, then it throws a TypeError
Python3
# creating a listfavourite_subject = ["OS", "DBMS", "Algo"]# creating a frozensetf_subject = frozenset(favourite_subject)# below line will generate errorf_subject[1] = "Networking" |
Output
TypeError Traceback (most recent call last)
Input In [13], in <cell line: 8>()
5 f_subject = frozenset(favourite_subject)
7 # below line will generate error
----> 8 f_subject[1] = "Networking"
TypeError: 'frozenset' object does not support item assignment
Frozenset operations
Frozen sets are immutable sets that allow you to perform various set operations such as union, intersection, difference, and symmetric difference.
Python3
# initialize A and BA = frozenset([1, 2, 3, 4])B = frozenset([3, 4, 5, 6])# copying a frozensetC = A.copy()print(C) # unionunion_set = A.union(B)print(union_set)# intersectionintersection_set = A.intersection(B)print(intersection_set) difference_set = A.difference(B)print(difference_set)# symmetric_differencesymmetric_difference_set = A.symmetric_difference(B)print(symmetric_difference_set) |
Output
frozenset({1, 2, 3, 4})
frozenset({1, 2, 3, 4, 5, 6})
frozenset({3, 4})
frozenset({1, 2})
frozenset({1, 2, 5, 6})
