Python高手之路体验课 第 18 / 18 篇
结业项目-购物商城-参考答案
购物商城
# 需求:
用户可以注册，登陆和购物
启动程序后：
先打印提示信息，请用户选择要执行的操作
由于没有使用永久保存，所以用户必须先注册才能登陆
注册: 请用户输入用户名和密码，需要输入两次一样的密码来确认
把注册好的用户保存在程序中
登陆: 登陆时输入密码错误三次则退出程序
登陆成功后请用户输入工资，作为用户的余额
需要在程序中保存用户的登陆状态
购物:
允许用户根据商品编号购买商品，比如：
1 iPhone
2 macbook
3 bike
用户选择商品后，检测余额是否够，够就直接扣款，更新用户余额，不够就提醒
可随时退出，退出时，打印已购买商品和余额解题思路参考：
product_list = [
['IphoneXR', 9800],
['Coffee', 30],
['Mac Pro 2019', 25000],
["Albert's Python Book", 99],
['Bike', 199],
['ViVo X20', 2499],
]
shopping_cart = {}
current_user_info = []
user_info = []
while True:
print('''
1：Register
2：Login
3：Shop
''')
choice = input("""
Please choose the function by inputting corresponding number,
if you input q, you'll quit the program>>:""").strip()
# user registering
if choice == '1':
username = input('please input your username>>:').strip()
while True:
password1 = input('please input your password>>:').strip()
password2 = input('please verify your password>>:').strip()
if password1 == password2:
print('Register successfully, input 2 to login')
user_info.append([username, password1])
break
else:
print('The twice password are inconsistent. Please input again')
# user logining
elif choice == '2':
count = 0
tag = True
while tag:
if count == 3:
print("You've tried too many times. You'll quit the program")
break
username = input('username>>:').strip()
password = input('password>>:').strip()
# read the user data
for data in user_info:
username_db = data[0]
password_db = data[1]
# verify user data
if username == username_db and password == password_db:
print('Login successfully')
# update current user info
current_user_info.append(username)
while True:
salary = input('please input your salary>>:').strip()
if not salary.isdigit():
continue
salary = int(salary)
balance = salary
current_user_info.append(balance)
break
# update all user info
data.append(balance)
print('Hello %s, your balance is %s, input 3 to start shopping' % (
data[0], data[1]))
tag = False
break
else:
print('username or password is invalid')
count += 1
# user shopping
elif choice == '3':
if not current_user_info:
print('Please login first')
else:
# get user's balance, and then shop
username_of_db = current_user_info[0]
balance = current_user_info[1]
print(balance, type(balance))
print('Dear user[%s], your balance is [%s], wish you enjoy your shopping' % (
username_of_db,
balance
))
tag = True
while tag:
for index, product in enumerate(product_list):
print(index, product)
choice = input("Input the numbers of product. if you input q, you'll quit the program>>:").strip()
if choice.isdigit():
choice = int(choice)
if choice < 0 or choice >= len(product_list):
continue
product_name = product_list[choice][0]
product_price = product_list[choice][1]
if balance > product_price:
if product_name in shopping_cart: # You've bought the product
shopping_cart[product_name]['count'] += 1
else:
shopping_cart[product_name] = {'product_price': product_price, 'count': 1}
balance -= product_price # deduct money
current_user_info[1] = balance # update user's balance
print(
"Added product " + product_name + " into shopping cart,your current balance " + str(
balance))
else:
print(
"You can't afford the product. The price of the product is %s, and you're lack of %s yuan"
% (
product_price,
product_price - balance
))
print('your shopping cart is %s' % shopping_cart)
elif choice == 'q':
print(
"--------------------------------The goods list you've bought--------------------------------")
total_cost = 0
for i, key in enumerate(shopping_cart):
print('%s%23s%23s%23s%23s' % (
i,
key,
shopping_cart[key]['count'],
shopping_cart[key]['product_price'],
shopping_cart[key]['product_price'] * shopping_cart[key]['count']
))
total_cost += shopping_cart[key]['product_price'] * shopping_cart[key]['count']
print("""
your total expenditure: %s
your balance: %s
""" % (total_cost, balance))
while tag:
inp = input('Confirm purchase(yes/no?)>>: ').strip()
if inp not in ['Y', 'N', 'y', 'n', 'yes', 'no']:
continue
if inp in ['Y', 'y', 'yes']:
# read user info
for data in user_info:
if data[0] == username_of_db:
if len(data) == 3:
data[2] = balance
else:
data.append(balance)
print("You've bought successfully. Please wait for the goods patiently")
shopping_cart = {}
current_user_info = []
tag = False
else:
print('Invalid operation')
elif choice == 'q':
break
else:
print('Invalid operation')