# Set

### Set

Mutable collection data type. Set can be modified.

Set has unique features:

Set does not contain duplicate elements, every element in a set is unique

Membership testing against a set (search if a value is an element of a set) is hashmap, meaning search against a set is faster than against a list, which is linear search.

Example:

s={1,2,3,4,5,5}

You notice there are two 5s

When you print out s, you only see one 5, which is

{1, 2, 3, 4, 5}

You can convert a list to a set by using function set(), by doing so, you eliminate duplicate elements

l=\[1,2,3,4,5,5]

set(l)

l=\[1,2,3,4,5,5]

set(l)

{1, 2, 3, 4, 5}

To create an empty set, use function set()

s=set()

To add an element ‘a’ into s:

s.add(‘a’)

To delete element ‘a’ from s:

s.remove(‘a’)

Need to note:

Order of elements in a set is not guaranteed and consistent


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