Python课程设计 第 46 / 52 篇
第一阶段项目-参考答案
项目一：多级菜单
# 要求：
打印三级菜单如：汽车，种类，品牌，型号，可以自由发挥
可返回上一级
可随时退出程序menu = {
'汽车': {
'轿车': {
'宝马': {
'宝马760': {},
'宝马M5': {},
'宝马M3': {}
},
'奔驰': {
'奔驰C180': {},
'奔驰E260': {},
'奔驰S600': {},
},
'奥迪': {
'奥迪A4L': {},
},
},
'越野车': {
'保时捷': {
'保时捷Macan': {},
'保时捷Cayenne': {},
},
'路虎': {},
'英菲尼迪': {},
},
'卡车': {},
'公交车': {},
},
'飞机': {
'大飞机': {
"大1": {
'xxx': {}
}
},
'小飞机': {
'小1': {
'xxx': {}
}
},
'直升机': {},
},
'大炮': {}
}
# # part1（初步实现）：能够一层一层进入
# layers = [menu, ]
# while True:
# current_layer = layers[-1]
# for key in current_layer:
# print(key)
#
# choice = input('>>: ').strip()
#
# if choice not in current_layer:
# continue
#
# layers.append(current_layer[choice])
# part2（改进）：加上退出机制
layers = [menu, ]
while True:
if len(layers) == 0:
break
current_layer = layers[-1]
for key in current_layer:
print(key)
choice = input('>>: ').strip()
if choice == 'b':
layers.pop(-1)
continue
if choice == 'q':
break
if choice not in current_layer:
continue
layers.append(current_layer[choice])项目二：购物商城
# 需求:
用户名，密码和余额存放于文件中，格式为：Albert|Albert123|3000
启动程序后：
已注册用户===>先登录===>登录成功===>读取用户余额===>开始购物
登录过程中，用户密码输入超过三次则退出程序,
并将用户名添加到黑名单，再次启动程序登陆改用户名，提示用户禁止登陆
未注册用户===>先注册===>注册成功===>输入用户工资，即为用户余额===>开始购物
注册过程中，用户密码输入两次一样才可以注册
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，修改文件中用户余额，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：
import os
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 = []
db_file = r'db.txt'
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')
break
else:
print('The twice password are inconsistent. Please input again')
with open(db_file, 'a', encoding='utf-8') as file:
file.write('%s|%s\n' % (username, password1))
file.flush()
# user logining
elif choice == '2':
tag = True
count = 0
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
with open(db_file, 'r', encoding='utf-8') as f:
for line in f:
line = line.strip('\n')
user_info = line.split('|')
username_of_db = user_info[0]
password_of_db = user_info[1]
# verify user data
if username == username_of_db and password == password_of_db:
print('Login successfully')
if len(user_info) == 3:
balance_of_db = user_info[2]
balance = balance_of_db
balance = int(balance)
else:
while True:
salary = input('please input your salary>>:').strip()
if not salary.isdigit():
continue
salary = int(salary)
balance = salary
break
# append the username and balance into the list
current_user_info = [username_of_db, balance]
print('Hello %s, your balance is %s, input 3 to start shopping' % (
current_user_info[0], current_user_info[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('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']:
# write the balance into the file
src_file = db_file
dst_file = r'%s.swap' % db_file
with open(src_file, 'r', encoding='utf-8') as read_file, \
open(dst_file, 'w', encoding='utf-8') as write_file:
for line in read_file:
if line.startswith(username_of_db):
user_info_line_list = line.strip('\n').split('|')
balance_of_db = balance
balance_of_db = str(balance_of_db)
if len(user_info_line_list) == 2:
user_info_line_list.append(balance_of_db)
else:
user_info_line_list[-1] = balance_of_db
line = '|'.join(user_info_line_list) + '\n'
write_file.write(line)
os.remove(src_file)
os.rename(dst_file, src_file)
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')