• A set is a collection that is unordered and unindexed. In Python, sets are written with curly brackets({}).
• Every element is unique and must be immutable (which cannot be changed). but set itself mutable objects
• Sets are unordered, so the items will appear in random order.

• you can create a set using curly braces or using built-in function set().

Synatx:

setname={element}
setname1=set(elements)

Example: You can not create a blank set like this

blankset={}
print(type(blankset)) 

Output:

<class 'dict'>

Create blank Set using built in function

myset=set()
print(type(myset))

Output:

<class 'set'>

Create a set with 1,2,3,4 elements

myset={1,2,3,4}
print(myset)

Output:

{1,2,3,4}

• Set Can not Contain any mutable object such as list Example:

my_set = {1, 2, [3, 4]}

Output:

TypeError: unhashable type: 'list'

• You can not access Element referring by index because the set is unordered and the item has no index.
• You can use for loop for accessing the element as follows Example:

myset={1,2,3,4}
for i in myset:
    print(i)

Output

1
2
3
4

• in keyword is used to check the existence of an element in the set
• Return True if element exists in a set otherwise Return False

Example:

color={'red','green','blue'}
if('red' in color):
    print('red is present')
else:
    print('red is not found')

Output:

red is present

Example

color={'red','green','blue'}
length=len(color) 
print(length) 

Output:

3