python實現購物車功能和結算功能

import math
商品的信息字典
dict_commodity_info = {
    101: {"name": "屠龍刀", "price": 10000},
    102: {"name": "倚天劍", "price": 10000},
    103: {"name": "九陰白骨爪", "price": 8000},
    104: {"name": "九陽神功", "price": 9000},
    105: {"name": "降龍十八掌", "price": 8000},
    106: {"name": "乾坤大挪移", "price": 10000}
}
購買物品的列表
list_orders = []

def print_menu():
    print("-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=")
    print("1、購買商品")
    print("2、商品結算")
    print("3、退出系統")
    print("+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-")
    
def print_commodity_info():
    """
    打印商品信息
    :return: 
    """
    for key, value in dict_commodity_info.items():
        print("編號：%d，名稱：%s，單價：%d。" % (key, value["name"], value["price"]))
   
def choice_commodity():
    """
    用戶購買商品
    :return: 用戶購買商品編號和數量{"cid": 商品編號, "count": 數量}
    """
    while True:
        cid = int(input("請輸入商品編號："))
        if cid in dict_commodity_info:
            break
        else:
            print("該商品不存在")
    count = int(input("請輸入購買數量："))
    return {"cid": cid, "count": count}

def print_buying_info():
    """
    打印用戶購買的商品信息
    :return:
    """
    for item in list_orders:
        commodity_id = dict_commodity_info[item["cid"]]
        print("商品：%s，單價：%d,數量:%d." % (commodity_id["name"], commodity_id["price"], item["count"]))
    calculate_total_price()

def calculate_total_price():
    """
    計算用戶購買商品的總價格
    :return: 用戶購買商品的總價格(total_price)
    """
    total_price = 0
    for item in list_orders:
        commodity_id = dict_commodity_info[item["cid"]]
        total_price += commodity_id["price"] * item["count"]
    return total_price

def print_two_menu():
    """
    打印二級菜單
    :return:
    """
    print("-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=")
    print("1、繼續購物")
    print("2、結束購物")
    print("-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=")
    choice_two_menu()

def choice_two_menu():
    """
    二級菜單的選擇輸入
    :return:
    """
    choice = input("請選擇功能>")
    if choice == "1":
        buying()
    elif choice == "2":
        exit()
    else:
        print("輸入錯誤，請重新輸入")
        print_two_menu()

def total_prices():
    """
    用戶輸入價格，並計算價格
    :return:
    """
    if calculate_total_price() == 0:
        print("你沒有選擇商品，請選擇購買商品")
        buying()
    else:
        while True:
            input_money = float(input("總價%d元，請輸入金額：" % calculate_total_price()))
            if input_money >= calculate_total_price():
                print("購買成功，找回：%d元。" % (input_money - calculate_total_price()))
                list_orders.clear()
                print_two_menu()
            else:
                moneys = order_pay_money(input_money)
                if moneys >= calculate_total_price():
                    print("購買成功，找回：%d元。" % (moneys - calculate_total_price()))
                    list_orders.clear()
                    print_two_menu()

def order_pay_money(order_input_money):
    """
    當第一次支付的金額不夠時，進行第二次支付
    :param order_input_money: 第一次支付的錢
    :return: 第一次和第二次的總和
    """
    total_money = order_input_money
    total_moneys = 0
    print("金額不足.還需要支付%d元-_-" % (math.fabs(total_money - calculate_total_price())))
    two_input_money = float(input("請繼續支付%d元 >" % (math.fabs(total_money - calculate_total_price()))))
    total_moneys = total_money + two_input_money
    return total_moneys

def buying():
    """
    用戶選擇功能主菜單
    :return:
    """
    while True:
        print_menu()
        item = input("請選擇功能>")
        if item == "1":
            print_commodity_info()
            list_orders.append(choice_commodity())
            print("添加到購物車。")
        elif item == "2":
            print_buying_info()
            total_prices()
        elif item == "3":
            exit()
            
if __name__ == "__main__":
    buying()