面向对象编程实战

使用面向对象编程将图书管理系统进行改造

import os


class File:
    name = 'books.txt'

    def __init__(self):
        file = open(File.name, 'a', encoding='utf-8')
        file.close()


class Manage:

    def add(self):
        book = input('请您输入书名：')
        with open(File.name, 'a', encoding='utf-8') as file:
            file.write(book + '\n')
            print(f'{book}增加成功！')

    def delete(self):
        book = input('请您输入需要删除的书名：')
        file = open(File.name, 'r', encoding='utf-8')
        books = file.readlines()
        file.close()
        if book + '\n' in books:
            books.remove(book + '\n')
            file = open(File.name, 'w', encoding='utf-8')
            file.writelines(books)
            file.close()
            print(f'{book}删除成功！')
        else:
            print('您输入的书名不存在！')

    def modify(self):
        book = input('请您输入需要修改的书名：')
        file = open(File.name, 'r', encoding='utf-8')
        books = file.readlines()
        file.close()
        if book + '\n' in books:
            newbook = input('请您输入新的书名：')
            books[books.index(book + '\n')] = newbook + '\n'
            file = open(File.name, 'w', encoding='utf-8')
            file.writelines(books)
            file.close()
            print(f'{book}已修改为{newbook}！')
        else:
            print('您输入的书名不存在！')

    def search(self):
        size = os.path.getsize(File.name)
        if size == 0:
            print('目前没有图书！')
        else:
            with open('books.txt', 'r', encoding='utf-8') as file:
                for book in file:
                    print(f'书名:{book}')


class Interface(Manage):

    def main(self):
        while True:
            print('-' * 50)
            print('欢迎使用图书管理系统！')
            print('-' * 50)
            print('增加图书【1】删除图书【2】修改图书【3】查看图书【4】')
            print('-' * 50)
            num = input('请输入数字指令：')
            if num == '1':
                self.add()
            elif num == '2':
                self.delete()
            elif num == '3':
                self.modify()
            elif num == '4':
                self.search()
            else:
                print('您的输入错误！')


file = File()

interface = Interface()
interface.main()