购物车
import os
import datetime
def login(name,password): #用户登陆,用户名和密码验证，登陆成功则返回登陆次数
with open('userlist.txt', 'r+',encoding='UTF-8') as f:
line = f.readline()
while(line):
pos=f.tell()
line=f.readline()
if [name,password] == line.split()[0:2]:
times=int(line.split()[2])
line=line.replace(str(times).center(5,' '),str(times+1).center(5,' '))
f.seek(pos)
f.write(line)
return times+1
return None
def get_balance(name): #获取用户余额数据
with open('userlist.txt', 'r',encoding='UTF-8') as f:
line = f.readline()
for line in f:
if name == line.split()[0]:
return line.split()[3]
print("用户%s不存在，无法获取其余额信息！"%name)
return False
def update_balance(name,balance): #更新用户余额数据
with open('userlist.txt', 'r+',encoding='UTF-8') as f:
line = f.readline()
while(line):
pos1=f.tell()
line=f.readline()
if name == line.split()[0]:
pos1=pos1+line.find(line.split()[2].center(5,' '))+5
pos2=f.tell()
f.seek(pos1)
f.write(str(balance).rjust(pos2-pos1-2,' '))
return True
print("用户%s不存在，无法更新其余额信息！" % name)
return False
def inquire_cost_record(name): #查询用户历史消费记录
if os.path.isfile(''.join([name,'_cost_record.txt'])):
with open(''.join([name,'_cost_record.txt']), 'r',encoding='UTF-8') as f:
print("历史消费记录".center(40, '='))
print(f.read())
print("".center(46, '='))
return True
else:
print("您还没有任何历史消费记录！")
return False
def update_cost_record(name,shopping_list): #更新用户消费记录
if len(shopping_list)>0:
if not os.path.isfile(''.join([name, '_cost_record.txt'])): #第一次创建时第一行标上“商品 价格”
with open(''.join([name, '_cost_record.txt']), 'a',encoding='UTF-8') as f:
f.write("%-5s%+20s\n" % ('商品', '价格'))
f.write(''.join([datetime.datetime.now().strftime('%c'), ' 消费记录']).center(40,'-')) #写入消费时间信息方便后续查询
f.write('\n')
for product in shopping_list:
f.write("%-5s%+20s\n"%(product[0],str(product[1])))
else:
with open(''.join([name, '_cost_record.txt']), 'a',encoding='UTF-8') as f:
f.write(''.join([datetime.datetime.now().strftime('%c'), ' 消费记录']).center(40, '-'))
f.write('\n')
for product in shopping_list:
f.write("%-5s%+20s\n"%(product[0],str(product[1])))
return True
else:
print("您本次没有购买商品，不更新消费记录！")
return False
def shopping_chart(): #主函数，用户交互，函数调用，结果输出
product_list=[
('Iphone',5000),
('自行车',600),
('联想电脑',7800),
('衬衫',350),
('洗衣机',1000),
('矿泉水',3),
('手表',12000)
] #商店商品列表
shopping_list=[] #用户本次购买商品列表
while(True):
username = input("请输入用户名：")
password = input("请输入密码：")
login_times=login(username,password) #查询输入用户名和密码是否正确,正确则返回登陆次数
if login_times:
print('欢迎%s第%d次登陆!'.center(50,'*')%(username,login_times))
if login_times==1:
balance = input("请输入工资：") #第一次登陆输入账户资金
while(True):
if balance.isdigit():
balance=int(balance)
break
else:
balance = input("输入工资有误，请重新输入：")
else:
balance=int(get_balance(username)) #非第一次登陆从文件获取账户余额
while(True):
print("请选择您要查询消费记录还是购买商品：")
print("[0] 查询消费记录")
print("[1] 购买商品")
choice=input(">>>")
if choice.isdigit():
if int(choice)==0: #查询历史消费记录
inquire_cost_record(username)
elif int(choice)==1: #购买商品
while (True):
for index,item in enumerate(product_list):
print(index,item)
choice=input("请输入商品编号购买商品:")
if choice.isdigit():
if int(choice)>=0 and int(choice)<len(product_list):
if int(product_list[int(choice)][1])<balance: #检查余额是否充足，充足则商品购买成功
shopping_list.append(product_list[int(choice)])
balance = balance - int(product_list[int(choice)][1])
print("\033[31;1m%s\033[0m已加入购物车中，您的当前余额是\033[31;1m%s元\033[0m" %(product_list[int(choice)][0],balance))
else:
print("\033[41;1m您的余额只剩%s元，无法购买%s！\033[0m" %(balance,product_list[int(choice)][0]))
else:
print("输入编号错误，请重新输入!")
elif choice=='q': #退出账号登陆，退出前打印本次购买清单和余额信息，并更新到文件
if len(shopping_list)>0:
print("本次购买商品清单".center(50,'-'))
for product in shopping_list:
print("%-5s%+20s"%(product[0],str(product[1])))
print("".center(50, '-'))
print("您的余额：\033[31;1m%s元\033[0m"%balance)
update_cost_record(username,shopping_list)
update_balance(username, balance)
print("退出登陆！".center(50, '*'))
exit()
else:
print("您本次没有消费记录，欢迎下次购买！")
print("退出登陆！".center(50, '*'))
exit()
else:
print("选项输入错误，请重新输入！")
else:
print("选项输入错误，请重新输入！")
elif choice=='q': #退出账号登陆
print("退出登陆！".center(50, '*'))
exit()
else:
print("选项输入错误，请重新输入！")
break
else:
print('用户名或密码错误,请重新输入!')
shopping_chart() #主程序运行
