Python之购物车实战（练习字典、random函数）

import random
user_name = "guojie"
user_passwd = "123456"
shopping_list = {"苹果":5,"香蕉":10,"榴莲":15,"芒果":20,"梨":25}
#随机生成四位验证码
while True:
    user_code = random.choice(range(1000, 10000))  # 生成四位验证码,刷新一次生成一次
    user_code = ""#用于接收字符串
    num1 = random.choice(range(0,4))
    num2 = random.choice(range(0,4))
    num3 = random.choice(range(0,4))
    for  i in range(0,4):#循环四次，生成四位验证码
        if num1 == i:
            temp = chr(random.randint(65,90))#生成A-Z
        elif num2 == i:
            temp = chr(random.randint(97,122))#生成a-z
        elif num3 == i:
            temp = random.choice(['!','@','#','$','%','^','&','*','?'])#随机生成一个特殊字符
        else:
            temp = random.choice(range(0,10))#随机生成一个数字
        user_code += str(temp)
    user_shopping = {}  # 用户的购物
    print("验证码：%s" %(user_code))
    name = input("用户名：")
    password = input("密码：")
    code = input("验证码：")
    if name == user_name and password == user_passwd:#先判断用户名和密码
        if code == user_code:#验证验证码
            str1 = "欢迎光临鲜果超市"
            print("*"*5 + str1 + "*"*5)
            #向客户展示商品
            for i,j in shopping_list.items():
                print(i,j,"元/个")
            money = 0  # 金额
            flag = False
            while True:
                #判断用户输入的是否存在清单中
                user_input = input("购买:")
                if user_input in shopping_list:
                    value = shopping_list[user_input]#返回键值
                    how_much = int(input("请问购买几斤?:"))
                    if user_input in user_shopping:#判断第二次购买的与第一次购买的物品相同
                        value2 = user_shopping[user_input]#返回已经在字典中值
                        user_shopping[user_input] = how_much+value2
                    money = money +(value * how_much)#单价*个数
                    # 将客户购买的水果和斤数放在客户的字典中
                    user_shopping.setdefault(user_input, how_much)
                    #判断用户是否继续购买
                    gogo = input("继续购买？：")
                    if gogo == "是":
                        flag = True
                    else:
                        print("欢迎下次光临，共支付%d元" %(money),"清单：",user_shopping)
                        break#跳出内层循环
                else:
                    print("对不起，不存在该物品")
            break#跳出外层循环
        else:
            print("验证码不对")
    else:
        print("用户名密码错误")