用函数模拟简单的购物车（Python）

"""
购物车功能：
	a.引导用户输入金额
	b.给用户展示所有的商品
	c.引导用户输入需要进行的操作【添加  删除 结算购物车  退出】
	d.引导用户选择商品
	e.引导用户输入需要购买的商品数量
	f.添加到购物车【容器】
	g.整个循环的操作，循环的次数不确定

"""

def add():
    print(super_market)  # 超市商品列表
    print(price_list)              #商品价格表
    commodity = input("please input you need to add to your shopping basket:")          #请输入你需要添加的商品
    commodity_number = int(input("please input the number of commodity:"))              #请输入你需要添加的商品数量
    user_market[commodity] = commodity_number                                           #将商品加到用户购物车中
    super_market[commodity] -= commodity_number
    return
def dell():
     dell_name = input("please input you del name :")  # 移除的商品名称
     dell_number = int(input("please the number you del:"))                              #移除的商品的数量
     user_market[dell_name] -=dell_number                                                #将购物车中的商品移除
     super_market[dell_name] += dell_number                                              #商品放回后超市现有的商品数目
     print(user_market)
     return
def looking():
    print(super_market)
    print(user_market)
    return
def settlement():
     amout = 0
     print(user_market)
     for key in user_market:
         amout += user_market[key] * price_list[key]
     print(amout)
     if amout > money_user:                              #如果总价高于所带的金额，退出循环
         print("you money is not pay for,please take the full money!")
     return False
def exit():
    print("Thank you for your presence and welcome to come again next time!!")
    return False
money_user = int(input("please user input your take money:"))
super_market = {"apple":50,"watermelon":20,"nuddles":40,"drinks":30}
price_list = {"apple":2,"watermelon":10,"nuddles":6,"drinks":3}
user_market = {}
while True:
    operation = int(input("please input your operation\n(1.add****2.del****3.looking****4.settlement****5.exit) :"))
    if operation == 1:
        add()
    elif operation ==2:
        dell()
    elif operation ==3:
        looking()
    elif operation ==4:
        settlement()
        if settlement() == False:
            break
    elif operation ==5:
        exit()
        if exit() == False:
            break