Python – Summation of consecutive elements power

When it is required to add the consecutive elements power, an 'if' condition and a simple iteration along with the '**' operator are used. This technique calculates the sum of each element raised to the power of its consecutive frequency count.

Example

Below is a demonstration of the same ?

my_list = [21, 21, 23, 23, 45, 45, 45, 56, 56, 67]

print("The list is :")
print(my_list)

my_freq = 1
my_result = 0

for index in range(0, len(my_list) - 1):

    if my_list[index] != my_list[index + 1]:
        my_result = my_result + my_list[index] ** my_freq
        my_freq = 1

    else:
        my_freq += 1

my_result = my_result + my_list[len(my_list) - 1] ** my_freq

print("The resultant value is :")
print(my_result)

Output

The list is :
[21, 21, 23, 23, 45, 45, 45, 56, 56, 67]
The resultant value is :
95298

How It Works

Let's break down how the calculation works for each group of consecutive elements:

• 21 appears 2 times consecutively: 21² = 441

• 23 appears 2 times consecutively: 23² = 529

• 45 appears 3 times consecutively: 45³ = 91,125

• 56 appears 2 times consecutively: 56² = 3,136

• 67 appears 1 time: 67¹ = 67

Total: 441 + 529 + 91,125 + 3,136 + 67 = 95,298

Step-by-Step Explanation

• A list is defined and is displayed on the console.

• An integer for frequency and result are defined.

• The list is iterated over, and an 'if' condition is placed.

• It checks to see if consecutive elements are equal or not.

• If they are not equal, the element is raised to the power of its frequency and added to the result variable.

• The frequency variable is re-initialized to 1.

• Otherwise, the frequency variable is incremented by 1.

• After the loop, the last element is processed separately to handle the final group.

• This result variable is the output that is displayed on the console.

Alternative Approach Using groupby

You can also solve this problem using Python's itertools.groupby() for a more concise solution ?

from itertools import groupby

my_list = [21, 21, 23, 23, 45, 45, 45, 56, 56, 67]

print("The list is :")
print(my_list)

my_result = sum(key ** len(list(group)) for key, group in groupby(my_list))

print("The resultant value is :")
print(my_result)

The list is :
[21, 21, 23, 23, 45, 45, 45, 56, 56, 67]
The resultant value is :
95298

Conclusion

This technique efficiently calculates the sum of consecutive elements raised to their frequency power. The manual approach gives you full control over the iteration, while groupby() provides a more Pythonic and concise solution.