Python: Compute the sum of the three lowest positive numbers from a given list of numbers

Last update on May 24 2025 10:47:13 (UTC/GMT +8 hours)

Sum of Three Lowest Positives

Write a Python program to compute the sum of the three lowest positive numbers from a given list of numbers.

Sample Solution:

Python Code:

# Define a function named sum_three_smallest_nums that takes a list of numbers (lst) as an argument.
def sum_three_smallest_nums(lst):
    # Sum the three smallest positive numbers in the sorted list of positive numbers from the input list.
    return sum(sorted([x for x in lst if x > 0])[:3])

# Create a list of numbers for testing.
nums = [10, 20, 30, 40, 50, 60, 7]
# Print the original list of numbers.
print("Original list of numbers: ", nums)
# Print the sum of the three lowest positive numbers in the list.
print("Sum of the three lowest positive numbers of the said array: ", sum_three_smallest_nums(nums))

# Test with a different list of numbers.
nums = [1, 2, 3, 4, 5]
# Print the original list of numbers.
print("\nOriginal list of numbers: ", nums)
# Print the sum of the three lowest positive numbers in the list.
print("Sum of the three lowest positive numbers of the said array: ", sum_three_smallest_nums(nums))

# Test with another list of numbers that includes zero.
nums = [0, 1, 2, 3, 4, 5]
# Print the original list of numbers.
print("\nOriginal list of numbers: ", nums)
# Print the sum of the three lowest positive numbers in the list.
print("Sum of the three lowest positive numbers of the said array: ", sum_three_smallest_nums(nums))

Sample Output:

Original list of numbers:  [10, 20, 30, 40, 50, 60, 7]
Sum of the three lowest positive numbers of the said array:  37

Original list of numbers:  [1, 2, 3, 4, 5]
Sum of the three lowest positive numbers of the said array:  6

Original list of numbers:  [0, 1, 2, 3, 4, 5]
Sum of the three lowest positive numbers of the said array:  6

Explanation:

Here is a breakdown of the above Python code:

• Function Definition:
• The code defines a function named "sum_three_smallest_nums()" that takes a list of numbers (lst) as an argument.
• List Comprehension:
• The function uses list comprehension to filter positive numbers from the input list.
• Sorting and Summing:
• The positive numbers are sorted, and the sum of the three smallest positive numbers is calculated using slicing ([:3])

Visual Presentation:

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Python program to identify the three smallest positive numbers in a list and calculate their sum.
• Write a Python program to sort a list and sum the first three positive integers found.
• Write a Python program to filter positive numbers from an array, sort them, and compute the sum of the three lowest.
• Write a Python program to determine the sum of the three smallest positive values using a min-heap data structure.

Go to:

• Python Basic Exercises Home ↩
• Python Exercises Home ↩

Previous: Write a Python program that accept two strings and test if the letters in the second string are present in the first string.
Next: Write a Python program to replace all but the last five characters of a given string with "*" and returns the new string.

Python Code Editor:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.