solution

app/customer.py

@@ -0,0 +1,10 @@
+class Customer:
+    def __init__(self, customer: dict) -> None:
+        self.name = customer["name"]
+        self.product_cart = customer["product_cart"]
+        self.milk = self.product_cart["milk"]
+        self.bread = self.product_cart["bread"]
+        self.butter = self.product_cart["butter"]
+        self.location = customer["location"]
+        self.money = customer["money"]
+        self.car_consumption = customer["car"]["fuel_consumption"]

app/file_opening.py

@@ -0,0 +1,22 @@
+import os
+import json
+
+from app.customer import Customer
+from app.shop import Shop
+
+
+def file_open(name_of_file: str) -> dict:
+    current_dir = os.path.dirname(os.path.abspath(__file__))
+    config_path = os.path.join(current_dir, name_of_file)
+    with open(config_path) as f:
+        person_data = json.load(f)
+        shops = [Shop(shop) for shop in person_data["shops"]]
+        customers = [
+            Customer(customer) for customer in person_data["customers"]
+        ]
+        fuel_price = person_data["FUEL_PRICE"]
+        return {
+            "fuel_price": fuel_price,
+            "shops": shops,
+            "customers": customers
+        }

app/main.py

@@ -1,3 +1,53 @@
-def shop_trip():
-    # write your code here
-    pass
+from datetime import datetime
+
+from app.trip_cost import calculate_trip_cost
+from app.file_opening import file_open
+
+
+def shop_trip() -> None:
+    user_data = file_open("config.json")
+    fuel_price = user_data["fuel_price"]
+    customers = user_data["customers"]
+    shops = user_data["shops"]
+    for customer in customers:
+        cheeper_shop = dict()
+        print(f"{customer.name} has {customer.money} dollars")
+        for shop in shops:
+            cost = calculate_trip_cost(customer, shop, fuel_price)
+            cheeper_shop.update({cost: shop})
+            print(f"{customer.name}'s trip "
+                  f"to the {shop.name} costs "
+                  f"{cost}")
+        min_cost = min(list(cheeper_shop.keys()))
+        if min_cost <= customer.money:
+            customer.location = cheeper_shop[min_cost].location
+            print(f"{customer.name} rides to {cheeper_shop[min_cost].name}\n")
+        else:
+            print(f"{customer.name} doesn't have enough money "
+                  f"to make a purchase in any shop")
+            continue
+        price_all_milks = (cheeper_shop[min_cost].price_milk * customer.milk)
+        if price_all_milks == int(price_all_milks):
+            price_all_milks = int(price_all_milks)
+        price_all_breads = (
+            cheeper_shop[min_cost].price_bread * customer.bread
+        )
+        if price_all_breads == int(price_all_breads):
+            price_all_breads = int(price_all_breads)
+        price_all_butters = (
+            cheeper_shop[min_cost].price_butter * customer.butter
+        )
+        if price_all_butters == int(price_all_butters):
+            price_all_butters = int(price_all_butters)
+        total = price_all_breads + price_all_milks + price_all_butters
+        date = datetime(2021, 1, 4, 12, 33, 41).strftime("%d/%m/%Y %H:%M:%S")
+        print(f"Date: {date}")
+        print(f"Thanks, {customer.name}, for your purchase!"
+              "\nYou have bought:"
+              f"\n{customer.milk} milks for {price_all_milks} dollars"
+              f"\n{customer.bread} breads for {price_all_breads} dollars"
+              f"\n{customer.butter} butters for {price_all_butters} dollars"
+              f"\nTotal cost is {total} dollars"
+              f"\nSee you again!\n"
+              f"\n{customer.name} rides home\n"
+              f"{customer.name} now has {customer.money - min_cost} dollars\n")

app/shop.py

@@ -0,0 +1,8 @@
+class Shop:
+    def __init__(self, shop: dict) -> None:
+        self.name = shop["name"]
+        self.location = shop["location"]
+        self.products = shop["products"]
+        self.price_milk = self.products["milk"]
+        self.price_bread = self.products["bread"]
+        self.price_butter = self.products["butter"]

app/trip_cost.py

@@ -0,0 +1,17 @@
+from app.customer import Customer
+from app.shop import Shop
+
+
+def calculate_trip_cost(
+        customer: Customer,
+        shop: Shop,
+        fuel_price: float
+) -> float:
+    distance = (abs(customer.location[0] - shop.location[0])
+                ** 2 + abs(customer.location[1] - shop.location[1])
+                ** 2) ** 0.5
+    cost = ((distance * 2 * customer.car_consumption / 100 * fuel_price)
+            + customer.milk * shop.price_milk
+            + customer.butter * shop.price_butter
+            + customer.bread * shop.price_bread)
+    return round(cost, 2)