Python program to find the sum of Characters ascii values in String List

Given the string list, the task is to write a Python program to compute the summation value of each character’s ASCII value.

Examples:

Input : test_list = [“geeksforgeeks”, “teaches”, “discipline”] 
Output : [133, 61, 100] 
Explanation : Positional character summed to get required values.

Input : test_list = [“geeksforgeeks”, “discipline”] 
Output : [133, 100] 
Explanation : Positional character summed to get required values. 

Method 1 : Using ord() + loop

In this, we iterate each character in each string and keep on adding positional values to get its sum. The summed value is appended back to the result in a list.

Python3

# Python3 code to demonstrate working of
# Characters Positions Summation in String List
# Using ord() + loop

# initializing list
test_list = ["geeksforgeeks",
             "teaches", "us", "discipline"]

# printing original list
print("The original list is : " + str(test_list))

res = []
for sub in test_list:
    ascii_sum = 0

    # getting ascii value sum
    for ele in sub :
        ascii_sum += (ord(ele) - 96)

    res.append(ascii_sum)

# printing result
print("Position Summation List : " + str(res))

Output:

The original list is : [‘geeksforgeeks’, ‘teaches’, ‘us’, ‘discipline’] Position Summation List : [133, 61, 40, 100]

Time Complexity: O(n)
Auxiliary Space: O(n)

Method 2 : Using list comprehension + sum() + ord()

In this, we get summation using sum(), ord() is used to get the ASCII positional value, and list comprehension offers one-liner solution to this problem.

Python3

# Python3 code to demonstrate working of
# Characters Positional Summation in String List
# Using list comprehension + sum() + ord()

# initializing list
test_list = ["geeksforgeeks", "teaches",
             "us", "discipline"]

# printing original list
print("The original list is : " + str(test_list))

# sum() gets summation, list comprehension
# used to perform task in one line
res = [sum([ord(ele) - 96 for ele in sub]) for sub in test_list]

# printing result
print("Positional Summation List : " + str(res))

Output:

The original list is : [‘geeksforgeeks’, ‘teaches’, ‘us’, ‘discipline’] Position Summation List : [133, 61, 40, 100]

The time and space complexity for all the methods are the same:

Time Complexity : O(n²)
Auxiliary Space : O(n)

Method 3 : Using map and lambda

Here’s another approach using map() function to calculate the summation of ASCII values of each character:

Python3

# Python3 code to demonstrate working of
# Characters Positional Summation in String List
# Using map() function

# initializing list
test_list = ["geeksforgeeks", "teaches",
             "us", "discipline"]

# printing original list
print("The original list is : " + str(test_list))

# map() function to calculate sum of ASCII values
res = list(map(lambda x: sum(map(lambda y: ord(y) - 96, x)), test_list))

# printing result
print("Positional Summation List : " + str(res))

Output

The original list is : ['geeksforgeeks', 'teaches', 'us', 'discipline']
Positional Summation List : [133, 61, 40, 100]

This method also has the same time and space complexity as the other two methods, i.e.,
Time Complexity: O(n^2)
Auxiliary Space: O(n)

Method 4 : using the reduce function from the functools module along with a lambda function.

Step-by-step approach:

• Import the functools module.
• Initialize the list containing the strings.
• Define a lambda function that takes two arguments a and b, and returns the sum of their ordinal values (ASCII value – 96).
• Use the reduce function along with the lambda function to get the positional summation of the characters in each string.
• Print the resultant list.

Python3

import functools

# initializing list
test_list = ["geeksforgeeks", "teaches", "us", "discipline"]

# printing original list
print("The original list is : " + str(test_list))

# using reduce() + lambda to compute positional summation
res = [functools.reduce(lambda a, b: a + ord(b) - 96, sub, 0) for sub in test_list]

# printing result
print("Positional Summation List : " + str(res))

Output

The original list is : ['geeksforgeeks', 'teaches', 'us', 'discipline']
Positional Summation List : [133, 61, 40, 100]

Time complexity: O(n*m), where n is the number of strings in the list and m is the maximum length of any string.
Auxiliary space: O(n), as we are storing the positional summation of each string in a list.