(i) In Python, a set is another type of collection data type. A'Set is a mutable and an unordered collection of elements without duplicates.
(ii) That means the elements within a set cannot be repeated. This feature used to include membership testing and eliminating duplicate elements. 

Syntax:
# Tuple with n number elements
Tuple_Name (E1, E2, E3.......En)
# Elements of a tuple without parenthesis
Tuple_Name = El, E2, E3 ................. En

Python enables reverse or negative indexing for the list elements. Thus, python lists index in opposite order. The python sets -1 as the index value for the last element in list and -2 for the preceding element and so on. This is called as Reverse Indexing.

(i) List is an ordered set of elements. But, a dictionary is a data structure that is used for matching one element (Key) with another (Value).
(ii) The index values can be used to access a particular element. But, in dictionary key represents index. Remember that, key may be a nunmber of a string.
(iii)  Lists are used to look up a value whereas a dictionary is used to take one value and look up another value.

Set Operations :
(i) Union : It includes all elements from two or more sets.
(ii) Intersection : It includes the common elements in two sets.
(iii) Difference : It includes all elements that are in first set (say set A) but not in the second set (say set B).
(iv) Symmetric difference : It includes all the elements that are in two sets (say sets A and B) but not the one that are common to two sets.

Sort ( ) :
It sorts the element in list.
Syntax :
   List.sort(reverse=True|False,key=myfunc)
Sorts the element in list :
Both arguments are optional
(i) If reverse is set as True, list sorting is in descending order.
(ii) Ascending is default.
(iii) Key=myFunc; "myFunc" - the name of the user defined function that specifies the sorting criteria.
Example :
MyList = [Thilothamma', "Tharani', 'Anitha','SaiSree', 'Lavanya')
MyList.sort( )
print(MyList)
MyList.sort(reverse=True)
print(MyList)
Output :
['Anitha', 'Lavanya', 'SaiSree', 'Tharani', 'Thilothamma']
['Thilothamma', 'Tharani', 'SaiSree', 'Lavanya', 'Anitha']
 

The python supports the set operations such as Union, Intersection, difference and Symmetric difference.
i) Union:
It includes all elements from two or more sets

In python, the operator Iis used to union of two sets. The function union ( ) is also used to join two sets in python.
Example:
Program to Join (Union) two sets using union operator
set_A={2,4,6,8}
set_B={'A', 'B', 'C', 'D'}
U_set=set_A l set_B
print (U _set)
Output:
{2, 4, 6, 8, 'A', 'D', 'C', 'B'}
Example:
Program to Join (Union) two sets using union function.
set_A={2,4,6,8}
set_B={'A', 'B', 'C', 'D'}
set_ U=set_ A.Union(set_ B)
print(set_U)
Output:
{'D', 2, 4, 6, 8, 'B', 'C', 'A'}
ii) Intersection:
(i) It includes the common elements in two sets

The operator & is used to intersect two sets in python. The function intersection( ) is also used to intersect two sets in python.
Example:
Program to insert two sets using intersection operator
set_A={'A', 2, 4, 'D'}
set_B={'A', 'B', 'C', 'D'}
print(set_A & set_B)
Output:
{'A', 'D'}
Example:
Program to insect two sets using intersection function
set_A={'A', 2, 4, 'D'}
set_B={'A', 'B', 'C', 'D'}
print( set_A.intersection(set_B))
Output:
{'A', 'D'}
iii) Difference
It includes all elements that are in first set (say set A) but not in the second set (say set B)

The minus (-) operator is used to difference set operation in python. The function difference() is also sed to difference operation.
Example:
Program to difference of two sets using minus operator
set_A={'A', 2, 4, 'D'}
set_B={'A', 'B', 'C', 'D'}
print(set_A - set B)
Output
{2,4}
Example: 
Program to difference of two sets using difference function
set_A={'A', 2, 4, 'D'}
set_B={'A', 'B', 'C', 'D'}
print(set_A.difference( set_B))
Output:
{2,4}
iv) Symmetric difference:
It includes all the elements that are in two sets (say sets A and B) but not the one that are common to two sets.

The caret (^) operator is used to symmetric difference set operation in python. The function symmetric_difference( ) is also used to do the same operation.
Example:
Program to symmetric difference of two sets using caret operator
set_A={'A', 2, 4, 'D'}
set_B={'A', 'B', 'C', 'D'}
print(set_A ^ set_B)
Output:
{2, 4, 'B', 'C'}
Example:
Program to difference of two sets using symmetric difference function
set_A={'A', 2, 4, 'D'}
set_B={'A', 'B', 'C', 'D'}
print( se_A.symmetric_ difference (set_B))
Output:
{2, 4, 'B', 'C'}

Inserting elements in a list using insert ( ) :
(i) append ( ) function in Python is used to add more elements in a list. But, it includes elements at the end of a list.
(ii) If you want to include an element at your desired position, you can use insert ( ) function. The insert ( ) function is used to insert an element at any position of a list.
Syntax :
List.insert (position index, element)
Example :
>>> MyList=[34,98,47, Kannan,Gowrisankar','Lenin', 'Sreenivasan' ]
>>> print(MyList)
[34, 98, 47, 'Kannan', 'Gowrisankar', 'Lenin', 'Sreenivasan']
>>> MyList.insert(3, 'Ramakrishnan')
>>> print(MyList)
[34, 98, 47, 'Ramakrishnan', 'Kannan', 'Gowrisankar, 'Lenin', 'Sreenivasan']
Output : [34, 98, 47, 'Ramakrishnan', 'Kannan', 'Gowrisankar', 'Lenin', 'Sreenivasan']
(i) In the above cxample, insert( ) function inserts a new element 'Ramakrishnan' at the index value 3, ie. at the 4th position.
(ii) While inserting a new element in between the existing elements, at a particular location, the existing elements shifts one position to the right.