刷题 16-20

**刷题16-20**

### 题目16#### 题目描述设计一个简单的银行管理系统，包括以下功能：

* 用户注册* 登录* 账户余额查询* 季度转账* 季度提款#### 实现代码

class Bank:
 def __init__(self):
 self.users = {}

 def register(self, username, password, balance=0):
 """用户注册"""
 if username in self.users:
 print("用户名已存在")
 return False self.users[username] = {"password": password, "balance": balance}
 print("注册成功")
 return True def login(self, username, password):
 """登录"""
 if username not in self.users or self.users[username]["password"] != password:
 print("用户名或密码错误")
 return False print("登录成功")
 return True def query_balance(self, username):
 """账户余额查询"""
 if username not in self.users:
 print("用户不存在")
 return None balance = self.users[username]["balance"]
 print(f"当前余额为:{balance}")
 return balance def transfer(self, username_from, username_to, amount):
 """季度转账"""
 if username_from not in self.users or username_to not in self.users:
 print("用户不存在")
 return False from_balance = self.query_balance(username_from)
 to_balance = self.query_balance(username_to)
 if from_balance < amount:
 print("余额不足")
 return False self.users[username_from]["balance"] -= amount self.users[username_to]["balance"] += amount print(f"转账成功，{amount}元从{username_from}转到{username_to}")
 return True def withdraw(self, username, amount):
 """季度提款"""
 if username not in self.users:
 print("用户不存在")
 return False balance = self.query_balance(username)
 if balance < amount:
 print("余额不足")
 return False self.users[username]["balance"] -= amount print(f"提款成功，{amount}元从{username}账户中取出")
 return Truebank = Bank()
while True:
 print("
1. 注册
2. 登录
3. 账户余额查询
4. 季度转账
5. 季度提款
6.退出")
 choice = input("请输入您的选择:")
 if choice == "1":
 username = input("请输入用户名:")
 password = input("请输入密码:")
 bank.register(username, password)
 elif choice == "2":
 username = input("请输入用户名:")
 password = input("请输入密码:")
 bank.login(username, password)
 elif choice == "3":
 username = input("请输入用户名:")
 bank.query_balance(username)
 elif choice == "4":
 username_from = input("请输入转出账户:")
 username_to = input("请输入转入账户:")
 amount = int(input("请输入转账金额:"))
 bank.transfer(username_from, username_to, amount)
 elif choice == "5":
 username = input("请输入用户名:")
 amount = int(input("请输入提款金额:"))
 bank.withdraw(username, amount)
 elif choice == "6":
 print("退出成功")
 break

class Book:
 def __init__(self, title, author, status="未借"):
 self.title = title self.author = author self.status = statusclass Library:
 def __init__(self):
 self.books = []

 def add_book(self, book):
 """图书添加"""
 self.books.append(book)
 print(f"添加成功，{book.title}已加入图书馆")

 def query_book(self, title):
 """图书查询"""
 for book in self.books:
 if book.title == title:
 return book print("图书不存在")
 return None def borrow_book(self, title):
 """图书借出"""
 book = self.query_book(title)
 if book is not None and book.status == "未借":
 book.status = "已借"
 print(f"借出成功，{book.title}已被借出")
 return True elif book is not None:
 print("图书已经被借出")
 return False else:
 print("图书不存在")
 return False def return_book(self, title):
 """图书归还"""
 book = self.query_book(title)
 if book is not None and book.status == "已借":
 book.status = "未借"
 print(f"归还成功，{book.title}已被归还")
 return True elif book is not None:
 print("图书已经在馆")
 return False else:
 print("图书不存在")
 return Falselibrary = Library()
while True:
 print("
1. 添加图书
2. 查询图书
3. 借出图书
4. 归还图书
5.退出")
 choice = input("请输入您的选择:")
 if choice == "1":
 title = input("请输入图书标题:")
 author = input("请输入图书作者:")
 library.add_book(Book(title, author))
 elif choice == "2":
 title = input("请输入图书标题:")
 book = library.query_book(title)
 print(f"图书:{book.title},作者:{book.author}, 状态:{book.status}")
 elif choice == "3":
 title = input("请输入图书标题:")
 library.borrow_book(title)
 elif choice == "4":
 title = input("请输入图书标题:")
 library.return_book(title)
 elif choice == "5":
 print("退出成功")
 break

class Student:
 def __init__(self, name, age, grade):
 self.name = name self.age = age self.grade = grade self.score = {}

class School:
 def __init__(self):
 self.students = []

 def register_student(self, student):
 """学生注册"""
 self.students.append(student)
 print(f"注册成功，{student.name}已加入学生列表")

 def login_student(self, name, password):
 """学生登录"""
 for student in self.students:
 if student.name == name and student.password == password:
 return True print("学生不存在或密码错误")
 return False def query_student_info(self, name):
 """学生信息查询"""
 for student in self.students:
 if student.name == name:
 return student print("学生不存在")
 return None def input_score(self, name, subject, score):
 """学生成绩录入"""
 student = self.query_student_info(name)
 if student is not None:
 student.score[subject] = score print(f"成功录入{student.name}的{subject}成绩")
 return True else:
 print("学生不存在")
 return False def query_score(self, name):
 """学生成绩查询"""
 student = self.query_student_info(name)
 if student is not None:
 for subject, score in student.score.items():
 print(f"{subject}:{score}")
 return True else:
 print("学生不存在")
 return Falseschool = School()
while True:
 print("
1. 注册学生
2. 登录学生
3. 查询学生信息
4. 录入学生成绩
5. 查询学生成绩
6.退出")
 choice = input("请输入您的选择:")
 if choice == "1":
 name = input("请输入学生姓名:")
 age = int(input("请输入学生年龄:"))
 grade = input("请输入学生年级:")
 password = input("请输入学生密码:")
 school.register_student(Student(name, age, grade))
 elif choice == "2":
 name = input("请输入学生姓名:")
 password = input("请输入学生密码:")
 school.login_student(name, password)
 elif choice == "3":
 name = input("请输入学生姓名:")
 student = school.query_student_info(name)
 print(f"学生:{student.name}, 年龄:{student.age}, 年级:{student.grade}")
 elif choice == "4":
 name = input("请输入学生姓名:")
 subject = input("请输入科目:")
 score = int(input("请输入成绩:"))
 school.input_score(name, subject, score)
 elif choice == "5":
 name = input("请输入学生姓名:")
 school.query_score(name)
 elif choice == "6":
 print