Page 188 - AI Ver 3.0 Class 11
P. 188
Length = 5
'p' 'r' 'o' 'b' 'e'
positive index 0 1 2 3 4
negative index -5 -4 -3 -2 -1
In order to access an element in a list we need to use index operator [].
fruits = ["kiwi", "pineapple", "cherry", "orange"]
# Accessing elements using positive indexing
print(fruits[0]) # Output: kiwi
print(fruits[1]) # Output: pineapple
# Accessing elements using negative indexing
print(fruits[-1]) # Output: orange
print(fruits[-2]) # Output: cherry
Lists are mutable, so you can change their elements. Just specify the index value with the new element to be added.
fruits[1] = "blueberry"
print(fruits) # Output: ['kiwi', 'blueberry', 'cherry', 'orange']
Adding Elements
You can add elements to a list by using the append(), insert(), and extend() methods.
Using append() Function
You can only add one element at a time with append(). If you want to add multiple elements using append(), you
need to use loops. Tuples can also be added to a list using append() because tuples cannot be changed after they're
created. Unlike sets, you can add lists to an existing list using the append() function.
# Adding elements using append() function
fruits.append("strawberry")
print(fruits)
Output:
['kiwi', 'blueberry', 'cherry', 'orange', 'strawberry']
Using insert() Function
The append() function adds an element only to the end of a list. To add an element at a specific position, you need to
use the insert() function. Unlike append(), which takes only one argument (the value to add), insert() requires
two arguments: the position where you want to insert the element and the value itself.
fruits.insert(2, "banana")
print(fruits)
Output:
['kiwi', 'blueberry', 'banana', 'cherry', 'orange', 'strawberry']
Using extend() Function
The extend() method is used to add multiple elements to the end of a list at the same time.
# Adding elements using extend() function
fruits1=['apple', 'mango']
fruits.extend(fruits1)
print(fruits)
Output:
['kiwi', 'blueberry', 'banana', 'cherry', 'orange', 'strawberry', 'apple', 'mango']
186 Touchpad Artificial Intelligence (Ver. 3.0)-XI

