Just like the lists or tuples, a set in python is also one of the collection types. A set is unordered, unindexed, and unchangeable. It is written using curly braces.
Example of a set:
cities = {'Delhi', 'Mumbai', 'Hyderabad', 'Bhopal'}
print(cities)
Output:
{‘Delhi’, ‘Mumbai’, ‘Hyderabad’, ‘Bhopal’}
Set items are unordered
It means that the items do not have a defined order in a set. They may appear in a different order every time you use them. Moreover, they cannot be referred to by any index.
A set is unchangeable
Once you create a set, it cannot be changed. However, you can remove items and add new ones.
Duplicate items are not allowed in a set
A set cannot have multiple items with the same value. If you try to do so, the duplicate values will be ignored.
For example:
cities = {'Delhi', 'Mumbai', 'Delhi', 'Hyderabad', 'Bhopal'}
print(cities)
Output:
{‘Mumbai’, ‘Delhi’, ‘Hyderabad’, ‘Bhopal’}
How to determine the length of a set?
To find out the number of items in a set, we can use the len() function.
For example
cities = {'Delhi', 'Mumbai', 'Hyderabad', 'Bhopal'}
print(len(cities))
Output:
4
Data types in a set
Items in a set can be of any data type. They can be string, integers or boolean values.
cities = {'Delhi', 'Mumbai', 'Hyderabad', 'Bhopal'}
ids = {1,12,45,24,56}
marks = {True, False}
print(cities)
print(ids)
print(marks)
Output:
{‘Delhi’, ‘Mumbai’, ‘Hyderabad’, ‘Bhopal’}
{1,12,45,24,56}
{True, False}
Not only this, but a set can have mixed data type values.
sampleset = {'Delhi', 24, True, 'mango'}
Type of a set
A set is defined as an object with the data type ‘set’.
For example
cities = {'Delhi', 'Mumbai', 'Hyderabad', 'Bhopal'}
print(type(cities))
Output:
<class ‘set’>
Note: We have used the type function to determine the set’s type. The type function in python is used to get the type of an object.