Finding the Product of Elements Using an Index List in Python

Introduction

List is the type of data type in Python which is used to store multiple numbers, strings in a single variable. We can access the elements of list with the help of its index. In Python, each element has index values. It starts from 0 and followed by 1 for the second element similarly 2 for the third element. . For example, we have a list [2, 4, 6, 8] which contains 4 elements. We can use the indices to perform operations on particular element of the list.

Understanding the Problem

Now this is the time to understand the given problem in a sequential order. We will understand the given problem with the help of following example. Suppose we have a list of numbers [1,2,3,4,5]. We have to find out the product of specific elements based on their positions in the list. Lets create another list name it as index list. We will write the indices of the numbers, we want to multiply. Suppose the indices of the above list be [0,2,4]. We can say that we want to multiply the elements at position 0, 2, and 4. In the above problem the values at the indices 0,2, and 4 are 1,3, and 5. So the product of these values will be 1*3*5 which is equals to 15. This paragraph gives you the exact understanding of the finding the product of elements using as index list. In the next paragraph, we will understand ¬the procedure of solving the problem with help of python language.

Solving the Problem using Python

Here is the step by step process of finding the product of elements using index list. To write the program of finding the product of elements using index list, we have to follow these steps in sequential order. All the steps are mentioned below

Step 1: Defining the function

We will start the program by defining a function. This function will include the instructions that will help in finding the product of elements. The name of the function will be “Prouduct_of_elements” It will contain two arguments. One is the index list and the another one is list of elements.

Step 2: Initializing the product

Inside the function, we will initialise a variable named “product” to hold our final result. We will set its initial value to 1 , as if we multiply it by 1 will not affect the initial value.

Step 3: Iterating through the Index List

In this step we will traverse through each index in the given index list. We are going to use for loop for the above traversing. Basically for loop helps us to traverse every element of the list without the repeatation of the code.

Step 4: Accessing the Element

Accessing the element is easier with the help of their indices. We will use the indices of the elements in the form of their position. Any operation can be easily applied with help of this indices in python.

Step 5: Multiplying the Element

Now it’s a time to multiply the current element with the product. We can update the product by using “*=” operator, which we will multiply the current element with the element.

Step 6: Repeating the Process

Loops in python help to repeat the same process again and again. The loop will continue until we have visited all the indices in the index list. This will make sure that we have visited and performed operation on each and every element of the list.

Step 7: Returning the Product

After visiting each and every element of the list, we will receive the product of the specified elements. In the end, we will return the final product from the function.

Example

def product_of_elements(index_list, elements_list):
    product = 1
    for index in index_list:
        product *= elements_list[index]
    return product

indices = [0, 2, 4]
elements = [1, 2, 3, 4, 5]
result = product_of_elements(indices, elements)
print("the Product of elements using Index list in Python is ",result)

Output

 the Product of elements using Index list in Python is  15      

Example Usage and Output

When we will run the above code in Visual studio code IDE. we will be able to understand the working of the code. If we have a list of numbers [1, 2, 3, 4, 5] and the numbers at indices [0, 2, 4] we want to multiply. We will call the function “product_of_elements” by passing the indices and elements in the form of arguments. Now we will store the result in the variable named as “result”. After this we will print the value of “result” to see the calculated product.

When we will run the code, the elements at the position 0, 2, and 4 in the list that is 1, 3, 5 will get multiplied and this will be stored in the result variable. In this way 15 will be stored in the result variable.

Conclusion

The previous issue has shown us how to use an index list in Python to get the product of items. Python is the language that makes issues of this type the most simple to tackle. We have defined a function in the previous challenge. The result was then returned after we iterated over a list, accessed particular items, multiplied them, and returned them.result.