introduce the notion of accessing elements in a collection of numbers in python

How to create an array in Python

arr = [10, 20, 30, 40, 50]

Accessing elements of array using indexing

arr = [10, 20, 30, 40, 50]
print(arr[0])
print(arr[1])
print(arr[2])

Ans:

10
20
30

Accessing elements of array using negative indexing

arr = [10, 20, 30, 40, 50]
print(arr[-1])
print(arr[-2])
Ans.
50
40

Find length of an array using len()

brands = ["Coke", "Apple", "Google", "Microsoft", "Toyota"]
num_brands = len(brands)
print(num_brands)    Ans: 5