如何使用类编写简易模拟代码：实现条码添加商品及总价统计

Got it, let's build a clean, reusable class that checks all your boxes. First, a quick note: your initial barcode syntax was a bit off (it should be a dictionary, not a list with key-value pairs). We'll adjust that to map barcodes to product names, plus add a price mapping since we need to track individual product costs.

Here's the implementation:

class ProductManager:
    def __init__(self):
        # Initialize the required tracking lists
        self.product_list = []
        self.price = []
        
        # Barcode to product name mapping (fixed your initial syntax)
        self.barcode_to_product = {123: "banana", 234: "apple", 345: "orange", 456: "pear"}
        # Product name to price mapping (customize these values as needed)
        self.product_to_price = {"banana": 1.99, "apple": 1.49, "orange": 0.99, "pear": 2.49}

    def add_product(self, input_barcode):
        # Check if the entered barcode exists in our system
        if input_barcode in self.barcode_to_product:
            product_name = self.barcode_to_product[input_barcode]
            # Add the product and its price to the respective lists
            self.product_list.append(product_name)
            self.price.append(self.product_to_price[product_name])
            print(f"Successfully added {product_name} to your list!")
        else:
            print(f"Oops, barcode {input_barcode} isn't recognized. Try another one.")

    def get_total_price(self):
        # Calculate and return the sum of all added product prices
        total = sum(self.price)
        print(f"Total cost of your selected products: ${total:.2f}")
        return total

How to use this class: #

• Create an instance of ProductManager
• Call add_product() with a barcode number to add items
• Use get_total_price() to compute the sum of all added products

Example walkthrough:

# Set up the product manager
shopping_manager = ProductManager()

# Add items using their barcodes
shopping_manager.add_product(123)  # Adds banana
shopping_manager.add_product(456)  # Adds pear
shopping_manager.add_product(234)  # Adds apple

# Calculate the total
shopping_manager.get_total_price()  # Output: Total cost of your selected products: $5.97

# Check the tracked lists
print(shopping_manager.product_list)  # Output: ['banana', 'pear', 'apple']
print(shopping_manager.price)         # Output: [1.99, 2.49, 1.49]

Quick breakdown of key parts: #

• Initialization: We set up the two tracking lists, plus two dictionaries to keep barcode-to-product and product-to-price mappings organized (easy to update if you add new products later).
• Adding products: The add_product method validates the input barcode, finds the matching product, and updates both lists only if the barcode is valid.
• Total calculation: The get_total_price method uses Python's built-in sum() function for efficiency, and formats the result to 2 decimal places for readability.

You can easily extend this class—like adding a method to remove items, clear the lists, or display all selected products—if you need more functionality later.

内容的提问来源于stack exchange，提问作者M. Dobariya