作业：购物商城
商品展示，价格
买，加入购物车
付款，钱不够
代码如下：
import codecs #登录接口，用户名密码都正确登录成功，否则失败 def login(your_name,your_password): with open("user_file","r") as l: for line in l: user_name,user_password,user_balance=line.strip().split(":") if your_name == user_name and your_password == user_password: flag = 1 break else: print("用户名或密码错误") flag = 0 return flag #商品展示列表 def show_goods(): print(10*'*' + "商品列表" + 10*"*") print(30 * "-") print("| 编号 | 名称 | 价格 | 数量 | ") try: with codecs.open("goods_file","r","utf-8") as f1: for line in f1: (goods_id,goods_name,goods_rate,goods_num) = line.strip().split(":") print(30 * "-") print('| %s | %s | %s | %s |' %(goods_id,goods_name,goods_rate,goods_num)) print(30*"-") # print("购买商品请输入产品编号/返回请输入b/退出请输入q") # the_num = input("请选择：") except ValueError: pass #展示购物车 def show_gouwuche(your_name): with codecs.open("gouwuche","r","utf-8") as f2: n = 0 print(30 * "-") print("| 编号 | 名称 | 数量 | 总价 |") for line in f2: user_name,goods_name,goods_num,goods_rate = line.strip().split(":") if user_name == your_name: n += 1 print(30 * "-") print(" | %s | %s | %s | %s |" %(n,goods_name,goods_num,goods_rate)) print(30*"-") #查看当前用户已购产品 def show_yigou(your_name): with codecs.open("yigoushangpin","r","utf-8") as f3: n = 0 print(30*"-") print("| 编号 | 名称 | 数量 | 总价 |") for line in f3: user_name,goods_name,goods_num,goods_rate = line.strip().split(":") if user_name == your_name: n += 1 print(30*"-") print('| %s | %s | %s | %s |' %(n,goods_name,goods_num,goods_rate)) print(30*"-") #账户余数查看 def show_money(your_name): with open("user_file","r") as l: for line in l: user_name,user_password,user_blance = line.strip().split(":") if your_name == user_name: print("您当前账户余额为：%s" %user_blance) break # 账户余额查看 def show_money(your_name): with open('user_file', 'r') as l: for line in l: user_name, user_password, user_balance = line.strip().split(':') if your_name == user_name: print('您当前账户余额为:%s' % user_balance) break #加入购物车，如果购物车中已经存在该商品则将商品数量相加，商品价格相加；如果购物车中不存在该商品，则添加到购物车中，并将可购买的库存量 def add_gouwuche(n,your_name): with codecs.open("goods_file","r+","utf-8") as f1: for line1 in f1: goods_id,goods_name,goods_rate,goods_num = line1.strip().split(":") if n == goods_id: goods_quantity = input("请输入数量：") #如果输入的并非数字则不合法，输入的数量大于库存，均需要重新输入 while True: if goods_quantity.isdigit(): if int(goods_num) < int(goods_quantity): goods_quantity = input("您输入的数量大于当前库克数量，请重新输入数量：") else: break else: goods_quantity = input("您输入的不合法，请重新输入数量：") with codecs.open("gouwuche","r+","utf-8") as f2: for line2 in f2: che_user_name,che_goods_name,che_goods_num,che_goods_rate = line2.strip().split(":") #判断当前选择的商品是否在购物车存在，如果存在标志位che_flag = 1 if your_name == che_user_name and goods_name == che_goods_name: che_flag = 1 che_goods_num = str(int(che_goods_num) + int(goods_quantity)) che_goods_rate = str(int(che_goods_rate) + int(goods_rate)*int(goods_quantity)) old_line = line2 new_line = che_user_name + ":" + che_goods_name + ":" + che_goods_num + ":" + che_goods_rate + " " break #当前选择的商品购物车中不存在，标志位che_flag = 0 else: che_flag = 0 che_goods_rate = str(int(goods_rate) * int(goods_quantity)) che_goods_num = goods_quantity che_goods_name = goods_name che_user_name = your_name new_line = ("%s:%s:%s:%s " %(che_user_name,che_goods_name,che_goods_num,che_goods_rate)) #购物车中存在，则将购物车中的数量更新，总价格更新 if che_flag == 1: f2.seek(0) old_gouwuche = f2.read() new_gouwuche = old_gouwuche.replace(old_line,new_line) f2.seek(0) f2.truncate() f2.write(new_gouwuche) #购物车中不存在，则在购物车中添加 elif che_flag == 0: f2.seek(0) old_gouwuche =f2.read() new_gouwuche = old_gouwuche + new_line f2.seek(0) f2.truncate() f2.write(new_gouwuche) #加入购物车后，将商品列表中的数量更新 new_goods_num = str(int(goods_num) - int(goods_quantity)) old_goods_line = line1 new_goods_line = ("%s:%s:%s:%s " %(goods_id,goods_name,goods_rate,new_goods_num)) f1.seek(0) old_goods_file = f1.read() new_goods_file = old_goods_file.replace(old_goods_line,new_goods_line) f1.seek(0) f1.truncate() f1.write(new_goods_file) goods_flag = True break else: goods_flag = False print("抱歉您选择的商品不存在，请重新选择") return goods_flag #删除购物车的商品 def del_gouwuche(del_gouwuche_num,your_name): with codecs.open("gouwuche","r+","utf-8") as f1: while True: n = 0 for line in f1: user_name,goods_name,goods_num,goods_rate = line.strip().split(":") #判断删除的商品是否存在，若存在撒谎拿出标志位del_flag = 1 if user_name == your_name: n += 1 if int(del_gouwuche_num) == n: del_goods_name = goods_name del_goods_num = goods_num del_goods_line = line1 del_flag = 1 break #商品存在，进行删除 if del_flag == 1: f1.seek(0) gouwuche_file = f1.readlines() gouwuche_file.remove(del_goods_line) f1.seek(0) f1.truncate() for line in gouwuche_file: f1.write(line) #更新商品清单，将从购物车删除的加到商品清单中 with codecs.open("goods_file","r+","utf-8") as f2: for line2 in f2: old_goods_line = list(line2.strip().split(":")) old_line = line2.strip() if old_goods_line[1] == del_goods_name: old_goods_line[3] = str(int(old_goods_line[3])) + int(del_goods_num) new_goods_line = old_goods_line del_flag = 1 break if del_flag == 1: f2.seek(0) new_line = ":".join(new_goods_line) old_goods_file = f2.read() new_goods_file = old_goods_file.replace(old_line,new_line) f2.seek(0) f2.truncate() f2.write(new_goods_file) break #要删除的商品不存在，标志位del_flag = 0 else: del_flag = 0 print("您要删除的商品不存在，请重新输入编号！") break return del_flag #支付购物车商品 def pay_gouwuche(gouwuche_num,your_name): with codecs.open("gouwuche","r+","utf-8") as f1: while True: n = 0 for line1 in f1: user_name,goods_name,goods_num,goods_rate = line1.strip().split(":") #判断删除的商品是否存在，若存在删除标志位del_flag = 1 if user_name == your_name: n += 1 if int(gouwuche_num) == n: pay_goods_name = goods_name pay_goods_num = goods_num pay_goods_rate = goods_rate pay_goods_line = line1 #查看当前用户余额是否能够支付商品 with open("user_file","r+") as user_file: for line in user_file: user_name,user_password,user_balance = line.strip().split(":") if your_name == user_name: old_balance_line = line new_balance = int(user_balance) - int(goods_rate) break if new_balance < 0: print("您的当前预余额不足,请充值后再支付！ ") pay_flag = False break #大于等于0时，则可以支付，并更新账户余额 else: pay_flag = True new_balance_line = user_name + ":" + user_password + ":" + str(new_balance) + " " user_file.seek(0) old_user_file = user_file.read() new_user_file = old_user_file.replace(old_balance_line,new_balance.line) user_file.seek(0) user_file.truncate() user_file.write(new_user_file) break else: pay_flag = "" #商品存在，支付成功后进行删除 if pay_flag == True: f1.seek(0) gouwuche_file = f1.readlines() gouwuche_file.remove(pay_goods_line) f1.seek(0) f1.truncate() for line in gouwuche_file: f1.write(line) #更新已购买的商品清单，将已支付的商品加入到购买的清单中 with codecs.open("yigoushangpin","r+","utf-8") as f2: for line2 in f2: old_yigou_line = list(line2.strip().split(":")) old_line = line2.strip() #当已购商品清单存在该商品购买记录则将数量相加，总价格相加 if old_yigou_line[1] == pay_goods_name and old_yigou_line[0] == your_name: old_yigou_line[2] = str(int(old_yigou_line[2]) + int(pay_goods_num)) old_yigou_line[3] = str(int(old_yigou_line[3]) + int(pay_goods_rate)) new_yigou_line = old_yigou_line f2.seed(0) new_line = ":".join(new_yigou_line) old_yigou_file = f2.read() new_yigou_file = old_yigou_file.replace(old_line,new_line) f2.seed(0) f2.truncate() f2.write(new_yigou_file) break #当已购商品清单灭有购买记录，则附加购买记录 else: f2.seek(0) old_yigou_file = f2.read() new_yigou_file = old_yigou_file + pay_goods_line f2.seek(0) f2.truncate() f2.write(new_yigou_file) print(" ") print("恭喜你，支付成功！") break elif pay_flag == False: flag = True break #要删除的商品不存在，标志位del_flag = 0 else: pay_flag = False print("您要支付的商品不存在，请重新输入编号！") break return pay_flag #账户充值 def add_money(blance_num,your_name): with open("user_file","r+") as f: for line in f: user_name,user_passwd,user_balance = line.strip().split(":") if user_name == your_name: old_user_line = line new_user_balance = str(int(user_balance) + int(balance_num)) new_user_line = user_name + ":" + user_passwd + ":" + new_user_balance + " " break f.seek(0) old_user_file = f.read() new_user_file = old_user_file.replace(old_user_line,new_user_line) f.seek(0) old_user_file = f.read() new_user_file = old_user_file.replace(old_user_line,new_user_line) f.seek(0) f.truncate() f.write(new_user_file) def main(): your_name = input("请输入用户名：") your_password = input("请输入密码：") menu_num = "" #登录,用户名或密码错误重新输入 while True: if login(your_name,your_password): print("欢迎%s登录购物商城" %your_name) print(30 * "*") break else: your_name = input("请重新输入用户名：") your_password = input("请重新输入密码：") while True: print(30 * "*") print("欢迎来到主菜单，您可进行如下操作！") print(30 * "*") print("| 1 商品列表 | 2 查询购物车 | 3 查看已购商品 | 4 账户余额 | q 退出商城 |") if menu_num == "": menu_num = input("请输入：") #进入商品列表 elif menu_num == "1": while True: show_goods() print("| 请输入商品编号加入购物车 | 输入b返回主菜单 | 输入q退出商城 |") your_goods_num = input("请选择：") print(" ") #判断输入的是否为纯数字，如果是 if your_goods_num.isdigit(): while add_gouwuche(your_goods_num,your_name): #当商品加入购物车后直接返回给购物车 menu_num = "2" break break elif your_goods_num == 'b': menu_num = "" break elif your_goods_num == "q": print("您已退出商城！") else: print("您输入的不合法，请重新输入！ ") #查看购物车 elif menu_num == "2": while True: print(30 * "*") print("您当前购物车商品如下所示：") show_gouwuche(your_name) print("| 1 返回主菜单 | 2 删除商品 | 3 支付商品 | q 退出商城 |") gouwuche_menu_num = input("请输入：") print(" ") #返回主菜单 if gouwuche_menu_num == '1': menu_num = '' break #删除商品 elif gouwuche_menu_num == '2': while True: del_gouwuche_num = input("请输入要删除的商品编号，或者输入b返回：") if del_gouwuche_num == "b": break elif not del_gouwuche_num.isdigit(): print("您输入的不合法，请重新输入！ ") continue elif del_gouwuche(del_gouwuche_num,your_name): print("删除成功 ") break #支付商品 elif gouwuche_menu_num == "3": while True: pay_gouwuche_num = input("请输入要支付的商品编号，返回请输入b:") if pay_gouwuche_num.isdigit(): if pay_gouwuche(pay_gouwuche_num,your_name): break elif pay_gouwuche_num == "b": break else: print("您输入的不合法，请重新输入！") elif gouwuche_menu_num == "q": print("您已退出商城!") exit() else: print("您输入的不合法，请重新输入 ") #查看已购买记录 elif menu_num == "3": print(30 * "*") print("您已购买商品如下所示：") show_yigou(your_name) print("| 输入b返回主菜单 | 输入q退出程序 |") while True: yigou_input = input("请输入：") if yigou_input == "b": menu_num = "" print(" ") break elif yigou_input == "q": print("您已退出商城！ ") else: print("你输入的不合法，请重新输入! ") #查看账户信息 elif menu_num == "4": while True: print(30 * "-") print("您的账户信息如下所示：") show_money(your_name) print("| 1 充值账户 | b 返回主菜单 | q 退出商城 |") money_num == input("请输入：") if money_num == "1": print(30 * "-") add_money_num = input("请输入充值金额，输入b返回：") if add_money_num.isdigit(): add_money_num = input("请输入充值金额，输入b返回：") if add_money_num.isdigit(): add_money(add_money,your_name) print("恭喜你，充值成功！ ") continue elif add_money_num == "b": continue else: print("您输入的不合法，请重新输入！ ") continue elif money_num == "b": menu_num = "" break elif money_num == "q": print("您已退出商城!") exit() else: print("您输入的不合法，请重新输入 ") elif menu_num == "q": print("您已退出商城!") exit() else: print("您的输入不合法，请重新输入! ") if __name__ == '__main__': main()
上面代码是网上找的，准备自己好好写一遍，开始的时候没有什么思路，里面主要是对文件的操作，还有一些新的方法，都是常用的方法，但是平时自己不会用的。