Introduction to Python - Weekly Challenge 2-2

Delivery fee calculator

This is an original task for the position of a Software Engineer Intern at Wolt. More details on my GitHub Repo

Your task is to write a delivery fee calculator. This code is needed when a customer is ready with their shopping cart and we’d like to show them how much the delivery will cost. The delivery price depends on the cart value, the number of items in the cart, the time of the order, and the delivery distance.

1. Specification

Rules for calculating a delivery fee

• If the cart value is less than 10€, a small order surcharge is added to the delivery price. The surcharge is the difference between the cart value and 10€. For example if the cart value is 8.90€, the surcharge will be 1.10€.
• A delivery fee for the first 1000 meters (=1km) is 2€. If the delivery distance is longer than that, 1€ is added for every additional 500 meters that the courier needs to travel before reaching the destination. Even if the distance would be shorter than 500 meters, the minimum fee is always 1€.
  • Example 1: If the delivery distance is 1499 meters, the delivery fee is: 2€ base fee + 1€ for the additional 500 m => 3€
  • Example 2: If the delivery distance is 1500 meters, the delivery fee is: 2€ base fee + 1€ for the additional 500 m => 3€
  • Example 3: If the delivery distance is 1501 meters, the delivery fee is: 2€ base fee + 1€ for the first 500 m + 1€ for the second 500 m => 4€
• If the number of items is five or more, an additional 50 cent surcharge is added for each item above and including the fifth item. An extra “bulk” fee applies for more than 12 items of 1,20€
  • Example 1: If the number of items is 4, no extra surcharge
  • Example 2: If the number of items is 5, 50 cents surcharge is added
  • Example 3: If the number of items is 10, 3€ surcharge (6 x 50 cents) is added
  • Example 4: If the number of items is 13, 5,70€ surcharge is added ((9 * 50 cents) + 1,20€)
  • Example 5: If the number of items is 14, 6,20€ surcharge is added ((10 * 50 cents) + 1,20€)
• The delivery fee can never be more than 15€, including possible surcharges.
• The delivery is free (0€) when the cart value is equal or more than 200€.
• During the Friday rush, 3 - 7 PM, the delivery fee (the total fee including possible surcharges) will be multiplied by 1.2x. However, the fee still cannot be more than the max (15€). Timezone isn’t that important. The original task had the following timezone definition:

  Considering timezone, for simplicity, use UTC as a timezone in backend solutions (so Friday rush is 3 - 7 PM UTC). In frontend solutions, use the timezone of the browser (so Friday rush is 3 - 7 PM in the timezone of the browser).

2. Testing Data

Example 1:

{"cart_value": 790, "delivery_distance": 2235, "number_of_items": 4, "time": "2024-01-15T13:00:00Z"}

Field details

Field	Type	Description	Example value
cart_value	Integer	Value of the shopping cart in cents.	790 (790 cents = 7.90€)
delivery_distance	Integer	The distance between the store and customer’s location in meters.	2235 (2235 meters = 2.235 km)
number_of_items	Integer	The number of items in the customer’s shopping cart.	4 (customer has 4 items in the cart)
time	String	Order time in UTC in ISO format.	2024-01-15T13:00:00Z

Result Example 1:

{"delivery_fee": 710}

Field details

Field	Type	Description	Example value
delivery_fee	Integer	Calculated delivery fee in cents.	710 (710 cents = 7.10€)

Example 2 (From the Front End Mockup Image):

{"cart_value": 2000, "delivery_distance": 900, "number_of_items": 1, "time": "2021-10-21T13:00:00Z"}

Field details

Field	Type	Description	Example value
cart_value	Integer	Value of the shopping cart in cents.	2000 (2000 cents = 2.00€)
delivery_distance	Integer	The distance between the store and customer’s location in meters.	900 (900 meters = 0.9 km)
number_of_items	Integer	The number of items in the customer’s shopping cart.	1 (customer has 1 items in the cart)
time	String	Order time in UTC in ISO format.	2021-10-21T13:00:00Z

Result Example 2:

{"delivery_fee": 200}