Page 443 - ComputerScience_Class_11

3. Nested List: A nested list is a list that contains one or more lists as its elements. It means a list inside another list,
used to store data in a structured or tabular form.
Program 9: To store a list inside another list in a single list variable.

Program 9.py
File Edit Format Run Options Window Help

# Creating a nested list (list inside a list )
numbers = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
# Printing the nested list
print("The nested data is:", numbers)

Output
The nested data is: [[1, 2, 3], [4, 5, 6], [7, 8, 9]]

12.4.3 Tuple
A tuple is a sequence data type in Python that stores multiple values in an ordered form. The elements of a tuple are
enclosed in parentheses () and separated by commas. Each element has an index number starting from 0 and a tuple
is immutable, which means its elements cannot be changed after creation. Syntax of tuples are as follows:

tuple_name = (item1, item2, item3, ...)
Program 10: To store data in a variable using the tuple sequence data type.
Program 10.py

File Edit Format Run Options Window Help

# Creating a tuple
number = (10, 20, 30, 40)
# Printing the complete tuple
print(number)
# Accessing the element at index 1
print("The element at index 1: ", number[1])
# Accessing the element at index 0
print("The element at index 0: ", number[0])

Output

(10, 20, 30, 40)
The element at index 1: 20
The element at index 0: 10

Note: As explained earlier, if a list is like a shopping bag where you can keep things in any manner, a tuple
is like a sealed box. Once you put items inside and close the lid, you can look at what is inside, but you
cannot change anything.

Data Types in Python 441