标签：pass write com ict split int pen 列表 编写
作业：购物商城
商品展示，价格
买，加入购物车
付款，钱不够
具体实现了如下功能：
1、可购买的商品信息显示
2、显示购物车内的商品信息、数量、总金额
3、购物车内的商品数量进行增加、减少和商品的删除
4、用户余额的充值
5、用户购买完成进行结账，将最终余额回写到用户文件中。
一、用户文件说明：
kevin 123 50000 sky 123 54000 mobi 123 80000
其中第一列为用户名，第二列为密码，第三列为帐户余额。
二、流程图如下：
import sys,os,getpass,time def input_handle(s): ‘‘‘用户输入字符数字转化为数字‘‘‘ if s.isdigit(): #判断用户输入是否是字符数字 s = int(s) #是的话就进行转换 return s def framework(user="",init_money=‘‘,now_money=‘‘,recharge_money=‘‘,value=‘‘): ‘‘‘架构函数，展示用户的基本信息‘‘‘ os.system("clear") init_money = int(init_money) now_money = int(now_money) recharge_money = int(recharge_money) message = ‘‘‘ ******************************************************************************* \033[32;1m欢迎来到小猪猪购物商城\033[0m ******************************************************************************* 会员：%s\t金额：%d\t当前余额：%d\t充值金额：%d\t购物车:%d ‘‘‘ %(user,init_money,now_money,recharge_money,value) print(message) def goods_list_show(my_dict): ‘‘‘商品展示模块，用于展示商品‘‘‘ local_dict = {} ‘‘‘对商品列表进行遍历并加上数字编号‘‘‘ i = 1 print("商品列表：") print("=================================================================================================") print("%-5s %-15s %-10s %-10s %-10s" %("编号","商品名称","商品价格(元)","商品总数量(个)","商品剩余数量(个)")) for k in my_dict.keys(): v = my_dict[k] if type(v) == dict: print("%-5s %-20s %-15d %-18d %-10d" %(i,k,v[‘price‘],v[‘num‘],v[‘sum‘])) local_dict[i] = [k,v["price"],v[‘num‘],v[‘sum‘]] i += 1 print("=================================================================================================") return local_dict def cart_goods_show(show_dict): ‘‘‘显示购物车商品,并加上数字编号‘‘‘ show_all_sum = 0 show_all_num = 0 ‘‘‘对商品列表进行遍历并加上数字编号‘‘‘ message = (‘编号‘,"商品名称","商品价格(元)","商品总数量(个)","购买数量(个)","购买金额(元)") print("%-5s \t %-20s \t %-10s \t %-10s \t %-10s \t %-10s" %message) for k in show_dict: v = show_dict[k] if type(v) is dict: print("%-5s \t %-10s \t %-10d \t %-10d \t %-10d \t %-10d" %(k,v[0],v[1],v[2],v[3],v[4])) show_all_num += v[4] show_all_num += 1 print("请确认你购买的商品，总金额：%d元"%(show_all_sum)) return (show_all_sum,show_all_num) def cart_goods_modify(modify_dict,modify_goods_dict): ‘‘‘购物车商品修改列表‘‘‘ a_flag = 1 while a_flag: index = input("请输入商品编号|完成修改(q):" %modify_dict[index][2]) if len(index) != 0: index = input_handle(index) if index == "q": break elif index in modify_dict: b_flag = 1 name = modify_dict[index][0] while b_flag: num = input("请输入新的商品数量(最大值为%d)|完成修改(q)：" %modify_dict[index][2]) if len(num) != 0: num = input_handle(num) if num == ‘q‘: break elif num == 0: modify_goods_dict[name][‘num‘] = modify_dict[index][2] del modify_dict[index] b_flag = 0 elif num > 0 and num <= modify_dict[index][2]: modify_dict[index][3] = num modify_dict[index][4] = modify_dict[index][1] * num modify_goods_dict[name][‘num‘] = modify_dict[index][2] - num b_flag = 0 else: pass else: pass return (modify_dict,modify_goods_dict) def shopping_cart_show(my_cart,my_goods_dict): ‘‘‘购物车展示‘‘‘ print("欢迎来到你的购物车".center(80,"#")) goods_all_sum = 0 goods_all_num = 0 if my_cart: ‘‘‘调用购物车商品列表函数,并返回商品总金额和总数量‘‘‘ (goods_all_sum,goods_all_num) = cart_goods_show(my_cart) choice = input("请进行如下操作：修改记录(c)|继续购物(!c)") if choice == "c": (my_shop_cart,my_goods_dict) = cart_goods_modify(my_cart,my_goods_dict) (goods_all_sum,goods_all_num) = cart_goods_show(my_cart) else: pass else: print("您当前的购物车为空".center(80,"#")) time.sleep(2) return (goods_all_sum,goods_all_num,my_goods_dict) def balance_recharge(recharge_init_balance,recharge_now_balance,recharge_money): recharge_flag = 1 while recharge_flag: recharge_num = input("请输入充值金额|返回(b)|退出(q)：") if len(recharge_num) != 0: recharge_num = input_handle(recharge_num) if recharge_num == "q": sys.exit(0) elif recharge_num == ‘b‘: break elif type(recharge_flag) is int and recharge_num > 0: recharge_init_balance += recharge_num recharge_now_balance += recharge_num recharge_money += recharge_num recharge_flag = 0 print("充值成功，请查收".center(80,"#")) else: pass return (recharge_init_balance,recharge_now_balance,recharge_money) def user_billing(billing_list,my_cart,billing_balance): ‘‘‘结帐模块‘‘‘ print("欢迎来到结帐模块".center(80,"#")) if my_cart: ‘‘‘调用购物车商品列表函数‘‘‘ cart_goods_show(my_cart) billing_flag = input("请确认是否商品结算(y|n)：") if billing_flag == "y": billing_file = open("info.txt",‘w‘) for user_info in billing_list: billing_file.writelines(user_info) billing_file.close() sys.exit("结帐成功，您当前余额：%d".center(80,"#") %billing_balance) else: print("退出结算菜单，继续购物".center(80,"#")) time.sleep(2) else: print("您当前的购物车为空，无需结算！") time.sleep(2) ‘‘‘主程序开始‘‘‘ if __name__ == "__main__": goods_list = { ‘iphone6‘: {‘price‘:6000,‘num‘:10,‘sum‘:10}, ‘ipad‘: {‘price‘:3000,‘num‘:20,‘sum‘:20}, ‘mi4‘: {‘price‘:2000,‘num‘:43,‘sum‘:43}, ‘huawei6_plus‘: {‘price‘:1999,‘num‘:8,‘sum‘:8}, } i = 0 while i < 3: #只要用户登录不超过3次就不断循环 username = input("请输入用户名：") password = input("请输入密码：") user_file = open("info.txt",‘r‘) user_list = user_file.readlines() user_file.close() for user_line in user_list: ‘‘‘分别获取当前账号、密码和余额信息‘‘‘ user,passwd,init_balance = user_line.strip(‘\n‘).split() init_balance = int(init_balance) now_balance = init_balance my_goods_sum = 0 if user == username and password == passwd: user_shopping_cart = {} user_shopping_cart_count = 0 recharge_value = 0 line_num = user_list.index(user_line) first_flag = 1 while first_flag: ‘‘‘调用框架函数输出用户信息‘‘‘ framework(username,init_balance,now_balance,recharge_value,user_shopping_cart_count) goods_output_dict = goods_list_show(goods_list) #输出商品信息 goods_index = input("请选择菜单：输入商品编号 | 购物车(c) | 余额充值(r) | 结账(b) | 退出(q) :") if len(goods_index) != 0: goods_index = input_handle(goods_index) if goods_index == ‘q‘: sys.exit(0) elif goods_index == ‘c‘: ‘‘‘调用购物车显示函数，并返回购物车商品总金额‘‘‘ (my_goods_sum,user_shopping_cart_count,goods_list) = shopping_cart_show(user_shopping_cart,goods_list) now_balance = init_balance - my_goods_sum if now_balance < 0: print("您的余额不足，请及时充值！") time.sleep(2) elif goods_index == ‘r‘: (init_balance,now_balance,recharge_value) = balance_recharge(init_balance,now_balance,recharge_value) elif goods_index == ‘b‘: ‘‘‘更新用户的余额‘‘‘ user_list[line_num] = user + ‘ ‘ + passwd + ‘ ‘ + repr(now_balance) + ‘\n‘ user_billing(user_list,user_shopping_cart,now_balance) elif goods_index in goods_output_dict: ‘‘‘取出goods_index商品列表信息并进行赋值和展示‘‘‘ (goods_name,goods_price,goods_num) = (goods_output_dict[goods_index][0],goods_output_dict[goods_index][1],goods_output_dict[goods_index][2]) print(‘【 编号：%-5d \t 名称：%-15s \t 价格：%-5d（元） \t 数量：%-5d（个）】‘ % (goods_index, goods_name, goods_price, goods_num)) second_flag = 1 while second_flag: buy_num = input(‘请输入购买商品个数(最大值为%d) | 返回(b) | 退出(q): ‘ % goods_num) if len(buy_num) != 0: buy_num = input_handle(buy_num) if buy_num == ‘q‘: sys.exit(0) elif buy_num == ‘b‘: break elif type(buy_num) is int and buy_num > 0 and buy_num <= goods_num: my_goods_sum = goods_price * buy_num if my_goods_sum <= now_balance: print(‘购买商品 %s 总价格为 : %d‘ % (goods_name, my_goods_sum)) add_flag = input("请确认是否加入购物车（y | n)：") if add_flag == "y": ‘‘‘判断购物车不存在该商品‘‘‘ if goods_index not in user_shopping_cart: user_shopping_cart_count += 1 ‘‘‘购物车商品数量加一‘‘‘ user_shopping_cart[goods_index] = [goods_name,goods_price,goods_num,buy_num,my_goods_sum] else: user_shopping_cart[goods_index][3] += buy_num user_shopping_cart[goods_index][4] += my_goods_sum now_balance -= my_goods_sum goods_list[goods_name][‘num‘] -= buy_num second_flag = 0 else: break else: print("您的余额不足，请充值或重新选择，谢谢！") time.sleep(2) else: pass else: pass else: if i != 2: print(‘用户或密码错误，请重新输入，还有 %d 次机会‘ % (2 - i)) i += 1 else: sys.exit(‘用户或密码输入错误超过三次，退出系统,欢迎下次光临‘)
上述代码不难，难的是思路，思路很重要，要知道如何一步一步去操作，用的也都是我们常用的知识，其实归根揭底我们写程序，大部分使用的都是字符串，字典，列表的功能。还有一些模块之类的。在写程序的过程中，思路显得尤为重要。知道了思路，就考虑如何使用代码去实现，上面程序中学到了如下知识点；
1、输出格式对其：print("%-5s %-15s %-10s %-10s %-10s" %("编号","商品名称","商品价格(元)","商品总数量(个)","商品剩余数量(个)"))，上面代码能够实现对其格式的功能，让我们输出的字符串格式统一，比如上述代码中，编号左对齐5个字符，商品名称左对齐15个字符等等；
2、str.center()的使用，如print("欢迎来到你的购物车".center(80,"#"))；
标签：pass write com ict split int pen 列表 编写
原文地址：http://www.cnblogs.com/gengcx/p/6970102.html
