以类的形式写Python的pymysqlDB

在Python中，我们可以使用`pymysql`库来连接MySQL数据库，并将其封装成类的形式以便于管理和复用。以下是一个简单的例子，展示了如何创建一个名为`MysqlDB`的类，用于处理数据库操作：

import pymysql

class MysqlDB:
    def __init__(self, host='localhost', user='your_username', password='your_password', db='your_database'):
        self.conn = None
        self.connect_params = {
            'host': host,
            'user': user,
            'password': password,
            'db': db
        }
        
    def connect(self):
        self.conn = pymysql.connect(**self.connect_params)
        return self.conn
    
    def close(self):
        if self.conn is not None:
            self.conn.close()
    
    def execute_query(self, query):
        try:
            with self.conn.cursor() as cursor:
                cursor.execute(query)
                result = cursor.fetchall()
            return result
        except Exception as e:
            print(f"Error executing query: {e}")
    
    def insert_data(self, table_name, data_dict):
        try:
            keys, values = zip(*data_dict.items())
            placeholders = ', '.join(['%s'] * len(keys))
            query = f"INSERT INTO {table_name} ({', '.join(keys)}) VALUES ({placeholders})"
            with self.conn.cursor() as cursor:
                cursor.execute(query, values)
            self.conn.commit()
        except Exception as e:
            print(f"Error inserting data: {e}")

# 使用示例
db = MysqlDB(host="127.0.0.1", user="root", password="password", db="test_db")
try:
    db.connect()
    # 执行查询
    results = db.execute_query("SELECT * FROM users")
    for row in results:
        print(row)
    
    # 插入数据
    db.insert_data("users", {"name": "John Doe", "age": 30})
finally:
    db.close()