创建一个util文件，以助之后使用mysql功能更加方便

import pymysql

class Mydb:
    config = {
        'host':'localhost',
        'user':'root',
        'password':'2923322454',
        'db':'practice',

        'charset':'utf8'
    }

    def __init__(self):
        self.connection = pymysql.connect(**Mydb.config)
        self.cursor = self.connection.cursor()

    def close(self):
        # 在关闭时，先关闭游标，之后再关闭连接
        if self.cursor:
            self.cursor.close()
        if self.connection:
            self.connection.close()

    def exeDML(self,sql,*args):
        '''
          执行插入、更新和删除

          :sql:要执行的sql语句，此语句中不包含查询语句
          :*args:传入的参数
        '''
        try:
            count = self.cursor.execute(sql,args)
            # id是上一条插入的数据的id
            # id = self.connection.insert_id()
            # 提交事务
            self.connection.commit()
            return id
        except Exception as e:
            if self.connection:
                # 若提交事务失败，则回滚
                self.connection.rollback()
            print(e)
        finally:
            self.close()

    def queryone(self,sql,*args):
        try:
            # 返回查询到的第一条数据
            self.cursor.execute(sql,args)
            return self.cursor.fetchone()
        except Exception as e:
            print(e)
        finally:
            self.close()

    def queryall(self,sql,*args):
        try:
            # 返回查询到的全部数据
            self.cursor.execute(sql,args)
            return self.cursor.fetchall()
        except Exception as e:
            print(e)
        finally:
            self.close()

if __name__ == "__main__":
    db = Mydb()
    sql = 'SELECT * FROM titles'
    infos = db.queryall(sql)
    print(infos)