【Python】简易书籍管理程序

之前简单介绍了有关Python的面向对象中的类，这次就围绕"类"和json格式来做一个简单的代码程序，并且在后面还附带了数据。

import json
import re
import time

class BookManager:
    def __init__(self):
        self.books = {}  # 使用字典存储书籍信息，book_id

    # 导入书籍信息
    def load_books(self, filename):
        try:
            with open(filename, 'r', encoding='utf-8') as file:
                self.books = json.load(file)
                if not self.books:
                    return  # 如果字典为空，返回
        except (json.JSONDecodeError, FileNotFoundError):
            return  # 如果文件为空，或不存在，或无法解析，直接返回

    def save_books(self):
        filename = r'books.json'
        with open(filename, 'w', encoding='utf-8') as file:
            # 没有书籍信息就不保存，并直接退出
            if self.books == {}:
                exit()

            # 保存书籍信息，并退出
            json.dump(obj=self.books, fp=file, indent=4, ensure_ascii=False)
            exit()

    def register_book(self):
        print("请输入书籍信息：")
        book_id = input("书籍ID: ")
        isbn = input("ISBN: ")

        title = input("书名: ")
        author = input("作者: ")
        genre = input("类型: ")

        # 检验书籍的有效性
        if self.validate_isbn(isbn) and \
                self.validate_book_id(book_id) and \
                book_id not in self.books.keys():

            self.books[book_id] = {
                'title': title,
                'author': author,
                'book_id': book_id,
                'genre': genre,
                'isbn': isbn
            }
        else:
            print("书籍ID和ISBN无效或已存在。")

    def delete_book_by_id(self):
        book_id = input("输入要删除的书籍ID: ")
        if book_id in self.books.keys():
            del self.books[book_id]
            print("书籍已删除。")
        else:
            print("找不到该书籍。")

    def modify_book(self):
        book_id = input("输入要修改的书籍ID: ")
        if book_id in self.books.keys():
            print("输入新的书籍信息（如果不想修改某项，请直接按回车键）：")
            new_ISBN = input("ISBN: ")
            new_title = input("书名: ")
            new_author = input("作者: ")
            new_genre = input("类型: ")

            # 如果输入不为空，则更新相应的信息
            if new_ISBN:
                self.books[book_id]['ISBN'] = new_ISBN
            if new_title:
                self.books[book_id]['title'] = new_title
            if new_author:
                self.books[book_id]['author'] = new_author
            if new_genre:
                self.books[book_id]['genre'] = new_genre

            print("书籍信息已更新。")
        else:
            print("找不到该书籍。")

    def display_books(self):
        # 没有书籍信息，就返回
        if not self.books:
            print("暂无书籍信息。")
            return

        # 遍历所有书籍信息
        print("所有书籍如下: ")
        for index, book in enumerate(self.books.values(), start=1):
            print(index, book, sep='、', end='\n')

    def find_book_by_id(self):
        book_id = input("输入书籍ID: ")
        if book_id in self.books.keys():
            print(self.books[book_id])
        else:
            print("找不到该ID的书籍信息。")

    def find_book_by_title(self):
        title = input("输入书名: ")
        found = False

        for book in self.books.values():
            # 检查输入的书名是否为书籍标题的一部分
            if title in book['title']:
                print(f"{book}")
                found = True

        if not found:
            print("没有找到该书名的书籍。")

    def find_book_by_genre(self):
        genre = input("输入书籍类型: ")
        found = False
        index = 1

        for book in self.books.values():
            # 检查输入的书名是否为书籍标题的一部分
            if genre in book['genre']:
                print(f"{index}、{book}")
                index = index + 1
                found = True

        if not found:
            print("没有该类型书籍。")

    # 检验书籍的ISBN位数是否合理——13位数字
    def validate_isbn(self, isbn):
        pattern = r'^\d{13}$'
        return re.match(pattern, isbn) is not None

    # 检验书籍的ID是否符合——数字
    def validate_book_id(self, id):
        pattern = r'^\d+$'
        return re.match(pattern, id) is not None


def main():
    manager = BookManager()
    manager.load_books('books.json')

    # 以索引为关键字，创建一个字典来存储类方法
    options = {
        '1': manager.register_book,
        '2': manager.delete_book_by_id,
        '3': manager.modify_book,
        '4': manager.display_books,
        '5': manager.find_book_by_id,
        '6': manager.find_book_by_title,
        '7': manager.find_book_by_genre,
        '8': manager.save_books
    }

    while True:
        time.sleep(2)

        print("\n主菜单:")
        print("1. 登记书籍")
        print("2. 删除书籍")
        print("3. 修改书籍")
        print("4. 显示所有书籍")
        print("5. 按ID查找书籍")
        print("6. 按书名查找书籍")
        print("7. 按类型查找书籍")
        print("8. 保存并退出程序")
        choice = input("请选择操作: ")

        if choice in options.keys():
            options[choice]()
        else:
            print("无效选项，请重新选择。")


if __name__ == '__main__':
    main()

{
    "1": {
        "title": "云边有个小卖部",
        "author": "张嘉佳",
        "book_id": "1",
        "genre": "情感小说",
        "isbn": "9787540487645"
    },
    "2": {
        "title": "月亮和六便士",
        "author": "威廉·萨默塞特·毛姆",
        "book_id": "2",
        "genre": "文学经典",
        "isbn": "9787530216787"
    },
    "3": {
        "title": "解忧杂货店",
        "author": "东野圭吾",
        "book_id": "3",
        "genre": "悬疑小说",
        "isbn": "9787544270878"
    },
    "4": {
        "title": "挪威的森林",
        "author": "村上春树",
        "book_id": "4",
        "genre": "现代文学",
        "isbn": "9787544731703"
    },
    "5": {
        "title": "百年孤独",
        "author": "加西亚·马尔克斯",
        "book_id": "5",
        "genre": "魔幻现实主义",
        "isbn": "9787544268103"
    },
    "6": {
        "title": "活着",
        "author": "余华",
        "book_id": "6",
        "genre": "现实主义",
        "isbn": "9787506365437"
    },
    "7": {
        "title": "小王子",
        "author": "安托万·德·圣埃克苏佩里",
        "book_id": "7",
        "genre": "童话",
        "isbn": "9787020042494"
    },
    "8": {
        "title": "围城",
        "author": "钱钟书",
        "book_id": "8",
        "genre": "现代文学",
        "isbn": "9787020024759"
    },
    "9": {
        "title": "追风筝的人",
        "author": "卡勒德·胡赛尼",
        "book_id": "9",
        "genre": "现代文学",
        "isbn": "9787208061644"
    },
    "10": {
        "title": "苏菲的世界",
        "author": "乔斯坦·贾德",
        "book_id": "10",
        "genre": "哲学",
        "isbn": "9787532739824"
    },
    "11": {
        "title": "瓦尔登湖",
        "author": "亨利·大卫·梭罗",
        "book_id": "11",
        "genre": "自然写作",
        "isbn": "9787544261098"
    },
    "12": {
        "title": "简爱",
        "author": "夏洛蒂·勃朗特",
        "book_id": "12",
        "genre": "古典文学",
        "isbn": "9787544242516"
    },
    "13": {
        "title": "1984",
        "author": "乔治·奥威尔",
        "book_id": "13",
        "genre": "反乌托邦",
        "isbn": "9787208061643"
    },
    "14": {
        "title": "飘",
        "author": "玛格丽特·米切尔",
        "book_id": "14",
        "genre": "历史小说",
        "isbn": "9787532745115"
    },
    "15": {
        "title": "动物农场",
        "author": "乔治·奥威尔",
        "book_id": "15",
        "genre": "政治讽刺",
        "isbn": "9787532739138"
    },
    "16": {
        "title": "荆棘鸟",
        "author": "科琳·麦卡洛",
        "book_id": "16",
        "genre": "家庭史诗",
        "isbn": "9787208115279"
    },
    "17": {
        "title": "哈利波特与魔法石",
        "author": "J.K. 罗琳",
        "book_id": "17",
        "genre": "奇幻",
        "isbn": "9787020033430"
    },
    "18": {
        "title": "了不起的盖茨比",
        "author": "弗朗西斯·斯科特·菲茨杰拉德",
        "book_id": "18",
        "genre": "美国小说",
        "isbn": "9787532737974"
    },
    "19": {
        "title": "不可抗力",
        "author": "玛丽安娜·海拉",
        "book_id": "19",
        "genre": "现代小说",
        "isbn": "9787544291179"
    },
    "20": {
        "title": "我们仨",
        "author": "杨绛",
        "book_id": "20",
        "genre": "回忆录",
        "isbn": "9787530219214"
    },
    "21": {
        "title": "天才在左 疯子在右",
        "author": "高铭",
        "book_id": "21",
        "genre": "心理学",
        "isbn": "9787508657421"
    },
    "22": {
        "title": "我与地坛",
        "author": "史铁生",
        "book_id": "22",
        "genre": "散文",
        "isbn": "9787530216770"
    },
    "23": {
        "title": "地球往事",
        "author": "刘慈欣",
        "book_id": "23",
        "genre": "科幻",
        "isbn": "9787536692930"
    },
    "24": {
        "title": "平凡的世界",
        "author": "路遥",
        "book_id": "24",
        "genre": "现实主义",
        "isbn": "9787020016402"
    },
    "25": {
        "title": "无人生还",
        "author": "阿加莎·克里斯蒂",
        "book_id": "25",
        "genre": "悬疑",
        "isbn": "9787208060943"
    }
}