Calculating totals

Compute subtotal and tax-inclusive total.

In this lesson we'll sum the prices of the items in the cart. Prices are kept in a list; a for loop computes the total:

prices = [10, 20, 30]
total = 0
for price in prices:
    total += price
print(total)  # 60

total += price adds price to total at each iteration. This is the basic method for list sums.

Cart total

Imagine the cart has a list of item prices. To compute the cart total we use a for loop:

prices = [10, 20, 30]
total = 0
for price in prices:
    total += price
print("Total:", total)  # Total: 60

This structure is the basis of cart apps: the amount the user pays is computed this way.

Assign prices = [10, 20, 30]. Assign total = 0. Write for price in prices: total += price. Print print(total).

Show example solution

prices = [10, 20, 30]
total = 0
for price in prices:
    total += price
print(total)

Complete the total loop

total = 0
for price in prices:
    total ____ price

Show answer

total = 0
for price in prices:
    total += price