python3.5实现购物车

一、购物车实现：

购物车功能：

• 用户登录：密码错误三次锁定账户。
• 商品列表分页显示：输入页码查看指定页数商品信息。
• 已购买商品列表：显示已购买的物品列表；可以模糊查询已购买的商品并在终端打印。
• 充值：输入充值金额，对db.txt里的对应账户余额进行更改。

　　-源码：

　　　　db.txt

dylan|123|19840|3
elaine|123|10000000000064255|3
admin|123|99999999761000|3

　　　　shopping_cart.py

#!/usr/bin/env python
# -*- coding:utf-8 -*-
#----------------------------------------------
#@version:    3.6
#@author:   Dylan_wu
#@software:    PyCharm
#@file:    shopping_cart.py
#@time:    2017/4/24 13:57
#----------------------------------------------
import prettytable
import sys

def buy_goods(user_name,money,goods,total_goods,total_page_num):
    goods_num = 0  # 初始化购买商品总数量
    all_goods_price = 0  # 初始化商品总价
    buy_list = []  # 初始化购物列表
    print('33[1;32mUser Name:[%s]  Account Balance:[￥%s]33[0m'%(user_name,money))
    while True:
        try:
            print('33[1;32mTotal_GOODS_Num:[%s] Total_Page_Num:[%s]33[0m'%(total_goods,total_page_num))
            page_num = input('33[1;36mPlease choose the page number(Press[C]to Check_Out_List,[Q]to quit):33[0m')
            int_page_num = int(page_num)
            start = (int_page_num - 1) * 5
            end = int_page_num * 5
            print('33[1;35m+----+----+GOODS_LIST+-------+-------+33[0m')
            #########开始构建商品表（分页）#########
            table = prettytable.PrettyTable()
            table.field_names = ['ID','Name', 'Unit_Price','Stock']
            for i in goods[start:end]:
                table.add_row([i['id'],i['name'],i['price'],i['stock']])
            print(table)
            print('33[1;35m+----+------Page-[%s]---------+-------+33[0m' % page_num)
        except:
            if page_num == 'C':    #跳出循环，进入checkout
                break
            elif page_num == 'Q':    #结束程序
                exit()
            else:
                print('33[1;31mPlease enter a Page_num!33[0m')
                continue
        #########开始购买程序###########
        while True:
            choose_ID = input("33[1;36mWhich good do you want to buy?Please choose the ID(Press[B]to back,[Q]to quit):33[0m")
            try:
                int_ID = int(choose_ID)  # 输入商品序号转化为int类型，若不报错，向下执行
                if int_ID in [i['id'] for i in goods]:  # 判断商品序号是否存在
                    product_quantity = int(input("33[1;36mWhat`s the quantity of products you want to buy:33[0m"))
                    if product_quantity <= goods[int_ID-1]['stock'] and product_quantity != 0:    #若购买数量<=库存
                        goods[int_ID - 1]['stock'] -= product_quantity    #更改库存
                        goods_num += product_quantity    #更新购买总数
                        all_goods_price += (goods[int_ID - 1]['price']*product_quantity)  # 叠加商品价格
                        #########构造购物列表#########
                        buy_list.append({'ID': int_ID, 'name': goods[int_ID - 1]['name'], 'price': goods[int_ID - 1]['price'],'quantity':product_quantity})
                    elif product_quantity == 0:
                        print("33[1;31mThe quantity of products can`t be[0]!!!!33[0m")
                        continue
                    else:
                        print('33[1;31mUnder stock!!!!33[0m')
                        continue
                else:
                    print('33[1;31mYou choose wrong number or out of range!33[0m')
                    continue
            except :    # 输入值不能转化为int,报错走这里
                if choose_ID == 'B':    #重新开始循环，回到分页界面
                    break
                elif choose_ID == 'Q':    #结束程序
                    exit()
                else:
                    print('33[1;31mPlease input a legal value!33[0m')  # 打印报错
    print('33[1;36mGoods_Num:[%s] Total_Price:[￥%s]33[0m' % (goods_num, all_goods_price))
    return goods_num, all_goods_price, buy_list


def check_out_list(b_list):
    #########开始构建购物表#########
    while True:
        cart_table = prettytable.PrettyTable()
        cart_table.field_names = ['Product_ID', 'Product_Name', 'Unit_Price','Product_Quantity']
        search_name = input('33[1;36mEnter the product name you want to search in Check_out_list(Press[C]to Check_Out_List,[Q]to quit):33[0m')
        if search_name == 'C':
            break
        elif search_name == 'Q':
            exit()
        else:    #输入字符串，得到相应的搜索结果，找不结果返回空表格，不输入返回所有
            for i in b_list:
                if i['name'].find(search_name) != -1:
                    cart_table.add_row([i['ID'], i['name'], i['price'],i['quantity']])
            print(cart_table)


def check_out(user_name,account_balance,num,all_price):
    print('33[1;36mTotal_Num:[%s] Total_Price:[￥%s] Account_Balance:[￥%s]33[0m' % (num, all_price,account_balance))
    while True:
        choose_ID = input('33[1;36mDo you want to check out?Press[R]to recharge,[C]to check out,press[B]to back and clear the check_out_list[Q]to quit:33[0m')
        if choose_ID == 'C':    #选择C进行check_out
            if all_price <= int(account_balance):    #若总价少于余额
                print('33[1;32mThe consumption is ￥%s totally,thank You for Your Custom!33[0m'%(all_price))
                balance = int(account_balance) - all_price
                mod_user(user_name,2,str(balance))    #对db里的用户余额进行更改
                break
            else:
                print('33[1;31mSorry,your balance has been insufficient,please recharge.33[0m')
        elif choose_ID == 'B':    #选择B返回购物菜单(清空购物列表，刷新商品字典)
            GOODS = [
                {"id": 1, "name": "特斯拉", "price": 998, "stock": 10},
                {"id": 2, "name": "玛莎拉蒂", "price": 898, "stock": 10},
                {"id": 3, "name": "宾利", "price": 1998, "stock": 10},
                {"id": 4, "name": "保时捷", "price": 1000, "stock": 10},
                {"id": 5, "name": "丰田", "price": 298, "stock": 10},
                {"id": 6, "name": "本田", "price": 398, "stock": 10},
                {"id": 7, "name": "斯巴鲁", "price": 298, "stock": 10},
                {"id": 8, "name": "奥拓", "price": 100, "stock": 10},
                {"id": 9, "name": "尼桑", "price": 198, "stock": 10},
                {"id": 10, "name": "奥迪", "price": 598, "stock": 10},
                {"id": 11, "name": "奔驰", "price": 998, "stock": 10},
                {"id": 12, "name": "宝马", "price": 1000, "stock": 10},
                {"id": 13, "name": "兰博基尼", "price": 1998, "stock": 10},
                {"id": 14, "name": "GMC", "price": 9898, "stock": 10},
                {"id": 15, "name": "哈佛", "price": 398, "stock": 10},
                {"id": 16, "name": "路虎", "price": 900, "stock": 10},
                {"id": 17, "name": "悍马", "price": 998, "stock": 10},
                {"id": 18, "name": "别克", "price": 198, "stock": 10},
                {"id": 19, "name": "雪铁龙", "price": 198, "stock": 10},
                {"id": 20, "name": "福特", "price": 300, "stock": 10},
                {"id": 21, "name": "雪佛兰", "price": 398, "stock": 10},
            ]
            num, all_price, b_list = buy_goods(user_name,account_balance,GOODS,total_goods,total_page_num)
            check_out_list(b_list)
            check_out(user_name,account_balance,num,all_price)
            exit()
        elif choose_ID == 'R':    #选择R进行充值
            account_balance = user_recharge(user_name,account_balance)    #执行充值函数
        elif choose_ID == 'Q':    #选择Q退出程序
            exit()
        else:
            print('33[1;31mPlease press[R],[C]or[B],[Q]!33[0m')

def user_recharge(user_name,balance):
    while True:
        print('33[1;36mDear %s!Your Account_Balance is:[￥%s]33[0m' % (user_name, balance))
        recharge_num = input('33[1;36mPlease enter the amount you want to charge,press[B]to back,press[Q]to quit:33[0m')
        try:
            int_amount = int(recharge_num)    #int所输入余额，不报错走这里
            now_balance = str(int_amount + int(balance))    #计算并str充值后余额
            mod_user(user_name,2,now_balance)    #调用mod_user函数修改db里的账户余额
            print('33[1;32mRecharge success!33[0m')
            return now_balance    #返回充值后余额

        except ValueError as e:    #报错走这里（输入值不能int)
            if recharge_num == 'B':
                return balance
            elif recharge_num == 'Q':
                exit()
            else:
                print('33[1;31mPlease enter a valid value!33[0m')

#============================主程序=============================#
GOODS = [
    {"id":1,"name": "特斯拉", "price": 998,"stock":10},
    {"id":2,"name": "玛莎拉蒂", "price": 898,"stock":10},
    {"id":3,"name": "宾利", "price": 1998,"stock":10},
    {"id":4,"name": "保时捷", "price": 1000,"stock":10},
    {"id":5, "name": "丰田", "price": 298,"stock":10},
    {"id":6, "name": "本田", "price": 398,"stock":10},
    {"id":7, "name": "斯巴鲁", "price": 298,"stock":10},
    {"id":8, "name": "奥拓", "price": 100,"stock":10},
    {"id":9, "name": "尼桑", "price": 198,"stock":10},
    {"id":10, "name": "奥迪", "price": 598,"stock":10},
    {"id":11, "name": "奔驰", "price": 998,"stock":10},
    {"id":12, "name": "宝马", "price": 1000,"stock":10},
    {"id":13, "name": "兰博基尼", "price": 1998,"stock":10},
    {"id":14, "name": "GMC", "price": 9898,"stock":10},
    {"id":15, "name": "哈佛", "price": 398,"stock":10},
    {"id":16, "name": "路虎", "price": 900,"stock":10},
    {"id":17, "name": "悍马", "price": 998,"stock":10},
    {"id":18, "name": "别克", "price": 198,"stock":10},
    {"id":19, "name": "雪铁龙", "price": 198,"stock":10},
    {"id":20, "name": "福特", "price": 300,"stock":10},
    {"id":21, "name": "雪佛兰", "price": 398,"stock":10},
]

f = open('db.txt','r')
user_line = f.readlines()
f.close()
total_goods = len(GOODS)    #获取商品总数
if len(GOODS)%5 == 0:    #获取商品总页数
    total_page_num = len(GOODS)//5
else:
    total_page_num = len(GOODS)//5 + 1
#========================修改数据库函数===========================#
#=============='''以用户名为标识，修改相应位置的值'''==============#
def mod_user(username,key_num,key_values):
    for i in range(len(user_line)):
        new_list = user_line[i].strip('
').split('|')
        if username == new_list[0]:
            new_list[key_num] = key_values
            user_line[i] = '|'.join(new_list)+'
'    #构成新user_line
    f1 = open('db.txt', 'w')
    f1.writelines(user_line)    #新user_line保存到db
    f1.close()

while True:
    username = input('33[1mPlease input your username:33[0m')
    password = input('33[1mPlease input your password:33[0m')
    for user_info in user_line:
        user_name,pass_word,balance,locked = user_info.strip('
').split('|')

        if username == user_name and password == pass_word and int(locked) != 0:    #登录成功条件判断
            print('33[1;32mLogin Successful!!33[0m')
            num, all_price, b_list = buy_goods(user_name,balance, GOODS,total_goods,total_page_num)
            check_out_list(b_list)
            check_out(username,balance,num,all_price)
            exit()

        elif username == user_name and int(locked) == 0:    #登录被锁定用户条件判断
            print('33[1;31mThe username:[%s]has been locked!Please contact the system administrator!33[0m'%(user_name))
            sys.exit('33[1;32mGood Bye!33[0m')

        elif username == user_name and int(locked) != 0:    #登录用户密码错误，锁定数-1条件判断
            locked_count = int(locked)    #获取user_info中的locked
            print('33[1;31mYou password is incorrect!You have %s attempts left before you will be locked out of your account.33[0m'%(locked_count-1))
            locked_count-=1
            mod_user(username,3,str(locked_count))    #修改用户的locked

            if locked_count == 0:    #锁定数=0时，退出程序
                print('33[1;31mYou account has been locked!!!Please contact the system administrator!33[0m')
                sys.exit('33[1;32mGood Bye!33[0m')
            else:
                break
    print('33[1;31mYou username or password is wrong!!!33[0m')

二、部分功能展示：

用户登录：

     

登录失败三次，账户锁定：

再次无法登陆：

购买商品：

购买数量不能为0报错：

商品分页：

已购买商品列表查询功能：

　　-输入值进行模糊查询：

　　-不输入值显示所有已购买商品：

　　-输入不存在的值显示空列表：

充值功能：

结账：