Exercise 1: Sum Each Row

Given a grid of numbers, print the sum of each row.

grid = [
    [1, 2, 3],
    [4, 5, 6],
    [7, 8, 9]
]

Expected output:

Row 0: 6
Row 1: 15
Row 2: 24

Starter Code

grid = [
    [1, 2, 3],
    [4, 5, 6],
    [7, 8, 9]
]

for r in range(len(grid)):
    total = ___
    for num in ___:
        total += ___
    print(f"Row {r}: {total}")

Hints

Hint 1 — Initialize the total

Start each row's total at 0: total = 0

Hint 2 — What to loop over?

Loop over each number in the current row: for num in grid[r]:

Hint 3 — Adding up

Add each number to the total: total += num

Solution

Show Solution

grid = [
    [1, 2, 3],
    [4, 5, 6],
    [7, 8, 9]
]

for r in range(len(grid)):
    total = 0
    for num in grid[r]:
        total += num
    print(f"Row {r}: {total}")

How it works:

Outer loop goes through each row index (0, 1, 2)
For each row, reset total to 0
Inner loop adds up every number in that row
Print the row number and its sum

Sum Each Row

Exercise 1: Sum Each Row

Starter Code

Hints

Solution

Try it yourself

Code: Sum Each Row