Python Common List Literals and Operations – Examples & Explanation

In Python, we can add two or more lists. The addition is basically the merging of items of different lists into one list. This process is called concatenation of list in Python Programming Language.

list1 = [1,2,3]
list2 = [4,5,6]
list3 = list1 + list2

print(list3)

Output:
[1, 2, 3, 4, 5, 6]

In the above example, we concatenate list1 and list2 into a list3. The items of the second list are added at the end. Now we concatenate more than two lists.

list1 = [1,2,3]
list2 = [4,5,6]
list3 = [7,8,9,10]
list4 = ['a','b','c','d']
list5 = list1 + list2 + list3 + list4

print(list5)

Output:
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 'a', 'b', 'c', 'd']

Subtraction or deduction of a list from other list is not allowed in Python programming language. TypeError will occur if we do this.

list1 = [1,2,3,4]
list2 = [4,5,6]
list3 = list1 - list2

print(list3)

Output:
TypeError: unsupported operand type(s) for -: 'list' and 'list'


To repeat items of the list, we use multiplication operator ‘*’ with a number that tells how many time a list items be repeated.

list1 = [1,2,3,4]
repeatList2 = list1 * 2
repeatList5 = list1 * 5

print('List item is repeated for 2 times',repeatList2 )
print('List item is repeated for 5 times',repeatList5 )

Output:
('List item is repeated for 2 times', [1, 2, 3, 4, 1, 2, 3, 4])
('List item is repeated for 5 times', [1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4])

For loop is used to iterate list items. To output all items of the list we can use for loop. Look at the following example.

list1 = [1,2,3,4,5]
for y in list1:
    print(y)

Output:
1
2
3
4
5

To check whether a particular item is a member or an item of a list or not, we use in operator.

# If something is not a member of the list.
list1 = [1,2,3,4,5]

if 3 in list1:
    print('This is a member of a list')
else:
    print('This is not the member of the list')

Output:
This is a member of a list
In the above example 3 in list1 is a logical expression.
Let’s take another example where something is not the member of the list.

# If something is not a member of the list.
list1 = [1,2,3,4,5]
if 7 in list1:
    print('This is a member of a list')
else:
    print('This is not the member of the list')

Output:
This is not the member of the list