How to do an iterative sum in Python?

To perform an iterative sum in Python, you initialize a variable to zero and then loop through the elements you want to sum, adding each element to the variable in each iteration.

Step-by-Step Guide

Here's how you can do it:

1. Initialize a variable: Create a variable (e.g., sum_) and set its initial value to 0. This variable will store the cumulative sum.
2. Iterate through the elements: Use a for loop to iterate through the list, tuple, or any iterable containing the numbers you want to sum.
3. Add each element to the sum: Inside the loop, add each element to the sum_ variable.
4. Access the final sum: After the loop finishes, the sum_ variable will hold the total sum of all the elements.

Code Example

def iterative_sum(data):
    """
    Calculates the sum of elements in an iterable using iteration.

    Args:
        data: An iterable (e.g., list, tuple) containing numbers.

    Returns:
        The sum of all elements in the iterable.
    """
    sum_ = 0  # Initialize the sum to 0
    for element in data:
        sum_ += element  # Add each element to the sum
    return sum_

# Example usage:
my_list = [1, 2, 3, 4, 5]
total = iterative_sum(my_list)
print(f"The sum of the list is: {total}")  # Output: The sum of the list is: 15

my_tuple = (10, 20, 30)
total_tuple = iterative_sum(my_tuple)
print(f"The sum of the tuple is: {total_tuple}") # Output: The sum of the tuple is: 60

Explanation

In the example above:

• The iterative_sum function takes an iterable data as input.
• sum_ = 0 initializes the sum_ variable to zero.
• The for element in data: loop iterates through each element in the data iterable.
• sum_ += element adds the current element to the sum_ variable in each iteration.
• Finally, return sum_ returns the calculated sum.

This is a fundamental and efficient way to calculate the sum of elements in Python using iteration.