PR: Add Fallback for Price API

 import requests
 
 def get_product_price(product_id):
     response = requests.get(f'https://api.store.com/products/{product_id}')
    response.raise_for_status()
    return response.json()['price']
    try:
        response.raise_for_status()
        return response.json()['price']
    except (requests.RequestException, KeyError):
        return 0.0
 
 def calculate_order_total(items):
    total = 0
    total = 0.0
     for item in items:
         price = get_product_price(item['product_id'])
         total += price * item['quantity']
    if total <= 0:
        raise ValueError('Order total must be positive')
     return total
 
 def process_checkout(user, items):
    total = calculate_order_total(items)
    total = calculate_order_total(items)
    if total == 0.0:
        return {'status': 'empty_cart'}
     charge_user(user, total)
     return {'status': 'success', 'charged': total}