import pymysql import pandas as pd from pandas import DataFrame from sqlalchemy import create_engine class mysql():     def __init__(self,host,port,user,password,database):         self.host=host         self.port=port         self.user=user         self.password=password         self.database=database         self._conn = None         self.Connect()     def Connect(self):         if not self._conn:             self._conn=pymysql.connect(host=self.host,port=self.port,user=self.user,password= self.password,database=self.database,charset='utf8')     #查询数据库表中的所有数据     def Query(self,sql):         self.cursor = self._conn.cursor()         self.excute = self.cursor.execute(sql)         row_all = self.cursor.fetchall()         index = self.cursor.description         new_index=[]         for i in range(len(index)):             new_index.append(index[i][0])         data_sql=DataFrame(list(row_all),columns=new_index)         return data_sql     #数据保存到数据库     def my_keep(self,data,filename):         db_url = (         '{driver}://{user}:{pwd}@{host}:{port}/{name}?charset=utf8'.format(driver='mysql+pymysql', user=self.user,                                                                            port=self.port, pwd=self.password,                                                                            host=self.host, name=self.database))         my_engine = create_engine(db_url)         pd.io.sql.to_sql(data, filename, my_engine, schema=self.database, if_exists='replace', index=True,index_label=None)     def my_close(self):         self.cursor.close()         self._conn.close()