add book_manager

book_manager.py

@@ -0,0 +1,180 @@
+import json
+import os
+from datetime import datetime
+
+class BookManager:
+    """图书管理类，负责图书信息的增删改查操作"""
+    
+    def __init__(self, data_file='books.json'):
+        """初始化图书管理器，加载已有图书数据"""
+        self.data_file = data_file
+        self.books = self._load_books()
+    
+    def _load_books(self):
+        """从文件加载图书数据"""
+        if os.path.exists(self.data_file):
+            try:
+                with open(self.data_file, 'r', encoding='utf-8') as f:
+                    return json.load(f)
+            except (json.JSONDecodeError, IOError) as e:
+                print(f"加载图书数据失败: {e}")
+                return []
+        return []
+    
+    def _save_books(self):
+        """将图书数据保存到文件"""
+        try:
+            with open(self.data_file, 'w', encoding='utf-8') as f:
+                json.dump(self.books, f, ensure_ascii=False, indent=2)
+            return True
+        except IOError as e:
+            print(f"保存图书数据失败: {e}")
+            return False
+    
+    def add_book(self, isbn, title, author, category, quantity=1):
+        """
+        添加新图书
+        
+        参数:
+            isbn (str): 图书ISBN编号
+            title (str): 图书标题
+            author (str): 图书作者
+            category (str): 图书分类
+            quantity (int): 图书数量，默认为1
+            
+        返回:
+            bool: 添加成功返回True，失败返回False
+        """
+        # 检查ISBN是否已存在
+        for book in self.books:
+            if book['isbn'] == isbn:
+                print(f"错误: ISBN为 {isbn} 的图书已存在")
+                return False
+        
+        new_book = {
+            'isbn': isbn,
+            'title': title,
+            'author': author,
+            'category': category,
+            'quantity': quantity,
+            'available': quantity,  # 可借阅数量
+            'added_date': datetime.now().strftime("%Y-%m-%d %H:%M:%S")
+        }
+        
+        self.books.append(new_book)
+        return self._save_books()
+    
+    def search_books(self, keyword=None, category=None, author=None):
+        """
+        搜索图书
+        
+        参数:
+            keyword (str): 标题或ISBN中的关键词
+            category (str): 图书分类
+            author (str): 作者名
+            
+        返回:
+            list: 符合条件的图书列表
+        """
+        results = []
+        
+        for book in self.books:
+            match = True
+            
+            if keyword and keyword not in book['title'] and keyword not in book['isbn']:
+                match = False
+            if category and book['category'] != category:
+                match = False
+            if author and author not in book['author']:
+                match = False
+                
+            if match:
+                results.append(book)
+        
+        return results
+    
+    def update_book(self, isbn, **kwargs):
+        """
+        更新图书信息
+        
+        参数:
+            isbn (str): 图书ISBN编号
+           ** kwargs: 要更新的字段，如title, author, category, quantity等
+            
+        返回:
+            bool: 更新成功返回True，失败返回False
+        """
+        for book in self.books:
+            if book['isbn'] == isbn:
+                # 计算可借阅数量的变化
+                if 'quantity' in kwargs:
+                    quantity_change = kwargs['quantity'] - book['quantity']
+                    book['available'] += quantity_change
+                
+                # 更新字段
+                for key, value in kwargs.items():
+                    if key in book:
+                        book[key] = value
+                
+                return self._save_books()
+        
+        print(f"错误: 未找到ISBN为 {isbn} 的图书")
+        return False
+    
+    def delete_book(self, isbn):
+        """
+        删除图书
+        
+        参数:
+            isbn (str): 图书ISBN编号
+            
+        返回:
+            bool: 删除成功返回True，失败返回False
+        """
+        initial_count = len(self.books)
+        self.books = [book for book in self.books if book['isbn'] != isbn]
+        
+        if len(self.books) < initial_count:
+            return self._save_books()
+        
+        print(f"错误: 未找到ISBN为 {isbn} 的图书")
+        return False
+    
+    def get_book_details(self, isbn):
+        """获取图书详细信息"""
+        for book in self.books:
+            if book['isbn'] == isbn:
+                return book
+        return None
+    
+    def list_all_books(self):
+        """列出所有图书"""
+        return self.books
+
+
+# 示例用法
+if __name__ == "__main__":
+    manager = BookManager()
+    
+    # 添加示例图书
+    manager.add_book("9780134685991", "Effective Python", "Brett Slatkin", "Programming", 5)
+    manager.add_book("9780596007126", "Head First Design Patterns", "Eric Freeman", "Programming", 3)
+    manager.add_book("9780141988511", "Sapiens: A Brief History of Humankind", "Yuval Noah Harari", "History", 4)
+    
+    print("所有图书:")
+    for book in manager.list_all_books():
+        print(f"{book['title']} by {book['author']} (ISBN: {book['isbn']}) - 可借: {book['available']}/{book['quantity']}")
+    
+    print("\n搜索编程类图书:")
+    programming_books = manager.search_books(category="Programming")
+    for book in programming_books:
+        print(f"- {book['title']}")
+    
+    print("\n更新图书数量:")
+    manager.update_book("9780134685991", quantity=7)
+    book = manager.get_book_details("9780134685991")
+    print(f"更新后数量: {book['available']}/{book['quantity']}")
+    
+    print("\n删除图书:")
+    manager.delete_book("9780596007126")
+    print(f"删除后剩余图书数量: {len(manager.list_all_books())}")