Python Exercise: Find the sum of all the numbers in a list

Last update on April 22 2025 12:58:12 (UTC/GMT +8 hours)

2. Sum All Numbers in a List

Write a Python function to sum all the numbers in a list.

Sample Solution:

Python Code:

# Define a function named 'sum' that takes a list of numbers as input
def sum(numbers):
    # Initialize a variable 'total' to store the sum of numbers, starting at 0
    total = 0
    
    # Iterate through each element 'x' in the 'numbers' list
    for x in numbers:
        # Add the current element 'x' to the 'total'
        total += x
    
    # Return the final sum stored in the 'total' variable
    return total

# Print the result of calling the 'sum' function with a tuple of numbers (8, 2, 3, 0, 7)
print(sum((8, 2, 3, 0, 7))) 

Sample Output:

20

Explanation:

In the exercise above the code defines a function named "sum()" that takes a list of numbers as input and returns the sum of all the numbers in the list. The final print statement demonstrates the result of calling the "sum()" function with a tuple containing the numbers (8, 2, 3, 0, 7).

Pictorial presentation:

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Python function that uses a for-loop to sum all numbers in a list and returns the total.
• Write a Python function that uses recursion to compute the sum of all elements in a list.
• Write a Python function that uses the built-in sum() function to sum a list, then compare its output with a manually computed sum.
• Write a Python function that sums only the positive numbers from a list and ignores negatives, using list comprehension.

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