Lists and Tuples in Python

The program will produce an error.

The list my_list has 6 elements, so valid negative indices range from -1 to -6. The index -7 is out of range, hence Python cannot access any element at that position.

[34, 'Hi', 56.7, 'Hello', 'India', 'Happy']

The extend() function is used to add multiple elements at the end of a list. Here, the elements "India" and "Happy" are added to the existing list list_new as separate elements, not as a single list.

False

Reason — A list is created by placing data items inside square brackets [ ], separated by commas.

True

Reason — A list is mutable, so its elements can be modified or updated after the list is created.

True

Reason — Each element in a list is assigned a unique index value that helps in identifying and accessing the data items in the list.

True

Reason — The index values of a list are fixed and are automatically assigned starting from 0 in sequence. While the elements of a list can be changed or rearranged, the sequence of index values itself cannot be changed.

True

Reason — A tuple is immutable, so its elements cannot be removed or modified individually. Only the entire tuple can be deleted.

True

Reason — The sort() function is used to arrange the elements of a list in ascending or descending order, so it can be used to sort the data items of a list.

True

Reason — In Python, a tuple supports the index() method, which returns the position (index) of the first occurrence of the given element in the tuple (and raises an error if the element is not found).

False

Reason — The append() function adds an element only at the end of a list. To place an element at a desired position, the insert() function is used.

True

Reason — The in operator is used to check whether an element is present in the tuple.

False

Reason — Looping statements can be used to print all the elements of a tuple.

First

Reason — The index() method returns the index (position) of the first occurrence of the given element in a tuple/list. So, if the element appears multiple times, index() gives the first index value where it is found.

insert()

Reason — The insert() function is used to place an element at a desired position in a list.

tuple()

Reason — The tuple() function is used to convert a list into a tuple.

Nested list

Reason — A list created within another list is called a nested list.

append()

Reason — The append() function is used to add elements to an empty list.

Index

Reason — To access or print an individual element of a tuple, its index value is specified inside square brackets.

Reverse

Reason — The keyword reverse=True is used with the sort() function to arrange and print list elements in descending order.

Immutable

Reason — Tuples are immutable objects, which means their elements cannot be changed after creation.

1. Python offers a wide range of data structures often referred to as sequences.
2. In an empty list, the square brackets [] do not hold any value.
3. The len() function in Python can be used when we want to know the number of elements stored in a list.
4. A tuple is an ordered sequence of items having any number of elements of different data types.
5. Sorting is the process of arranging and displaying the elements of a list in ascending or descending order.

# Demonstrating difference between List and Tuple

# Creating a list
my_list = [10, 20, 30]
print("Original List:", my_list)

# Updating list element
my_list[1] = 25
print("Updated List:", my_list)

# Creating a tuple
my_tuple = (10, 20, 30)
print("Original Tuple:", my_tuple)

my_tuple[1] = 25
# Trying to update tuple element (will cause error)

my_tuple = (23, 45, 67, 89, 12)

for i in my_tuple:
    print(i)

23
45
67
89
12

numbers = [1,2,3,4,5,6,7,8,9,10]
squares = []
for i in numbers:
    squares.append(i * i)
print("Natural numbers:", numbers)
print("Squares of numbers:", squares)

Natural numbers: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
Squares of numbers: [1, 4, 9, 16, 25, 36, 49, 64, 81, 100]

marks_tuple = (82, 64, 91, 79, 94)
marks_list = list(marks_tuple)
print("Tuple:", marks_tuple)
print("List after conversion:", marks_list)
numbers_list = [10, 20, 30, 40, 50]
numbers_tuple = tuple(numbers_list)
print("List:", numbers_list)
print("Tuple after conversion:", numbers_tuple)

Tuple: (82, 64, 91, 79, 94)
List after conversion: [82, 64, 91, 79, 94]
List: [10, 20, 30, 40, 50]
Tuple after conversion: (10, 20, 30, 40, 50)

number = [45, 67, 12, 56, 78]
e = int(input("Enter the element to search: "))
if e in number:
    print("Element is found in the list.")
else:
    print("Element is not found in the list.")

Enter the element to search: 67
Element is found in the list.

numbers = [2, 3, 4, 5, 7]
for i in numbers:
    print(i * i)

4
9
16
25
49

numbers = [2, 3, 4, 5, 7]
total = 0
for i in numbers:
    total = total + i
print("Sum of elements:", total)

Sum of elements: 21

classmates = [
    ["Amit", 1],
    ["Neha", 2],
    ["Rohit", 3],
    ["Sneha", 4]
]
print("Roll number:", classmates[2][1])

Roll number: 3

Lists are not suitable when the data is fixed and should not be changed during program execution. In such cases, tuples are suitable because they are immutable (elements cannot be modified, added, or removed).

Example: Storing the days of the week.

days = ("Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday")

Benefit: A tuple prevents accidental changes, making the data safer and more reliable (also slightly more memory-efficient than a list).