Merge Data with Comprehension and Generator in Python

def merge_data(users, orders):
    """
    Merge user and order data using a dictionary comprehension
    and a generator expression for filtering.
    """
    # Build a lookup: user_id -> user name
    user_map = {user["id"]: user["name"] for user in users}

    # Generator: yield orders with user names attached
    merged = (
        {
            "order_id": order["id"],
            "user_name": user_map.get(order["user_id"], "Unknown"),
            "total": order["total"],
        }
        for order in orders
        if order["total"] > 50
    )

    return list(merged)


if __name__ == "__main__":
    users = [
        {"id": 1, "name": "Alice"},
        {"id": 2, "name": "Bob"},
        {"id": 3, "name": "Charlie"},
    ]
    orders = [
        {"id": 101, "user_id": 1, "total": 75.5},
        {"id": 102, "user_id": 2, "total": 20.0},
        {"id": 103, "user_id": 3, "total": 99.9},
        {"id": 104, "user_id": 99, "total": 60.0},
    ]

    result = merge_data(users, orders)
    print(result)