Set add() Method in Python (original) (raw)
Last Updated : 18 Apr, 2026
The set.add() method in Python adds a single element to a set. It automatically ignores duplicate values and only accepts immutable (hashable) types like numbers, strings and tuples. Mutable types such as lists or dictionaries cannot be added.
**Example: In this example, an empty set is created using set() function then an element 's' is added in the empty set 'a' using add() function.
Python `
a = set() a.add('s') print(a)
`
**Explanation: set() creates an empty set and a.add('s') adds 's' to the set
Syntax
set_name.add(element)
- **Parameter: **element - The value to be added to the set.
- **Returns: It does not return anything (None).
Examples
**Example 1: In this example, we add elements to a set of characters and observe that duplicate values are ignored.
Python `
a = {'g', 'e', 'k'}
a.add('s') print(a)
a.add('s') print(a)
`
Output
{'g', 'k', 's', 'e'} {'g', 'k', 's', 'e'}
**Explanation: a.add('s') adds 's' to the set and calling a.add('s') again does not change the set.
**Example 2: In this example, we add numbers to a set and see how duplicate values are handled.
Python `
a = {6, 0, 4}
a.add(1) print(a)
a.add(0) print(a)
`
Output
{0, 1, 4, 6} {0, 1, 4, 6}
**Explanation: a.add(1) inserts 1 into the set and a.add(0) does not change the set because 0 already exists.
**Example 3: Here, we add a tuple using add() and multiple elements from a list using update().
Python `
s = {'g', 'e', 'e', 'k', 's'} t = ('f', 'o') l = ['a', 'e']
s.add(t) s.update(l) print(s)
`
Output
{'k', 's', ('f', 'o'), 'g', 'e', 'a'}
**Explanation:
- Duplicate 'e' is removed when creating the set and s.add(t) adds the tuple ('f', 'o') as a single element
- s.update(l) adds elements of list l individually and duplicate 'e' from l is ignored.