从postgress 读取数据

import psycopg2
import pandas as pd

#本函数用于读取某只股票的历史数据，输入的code不是股票代码而是公司内部代码
def data(code):
    
    #连接数据库
    conn = psycopg2.connect(dbname="db_dev_django", user="db_user",
            password="密码", host="ip", port="5432")
    cur = conn.cursor()
    #select * from choice_dailyfinancehistory where id='601857' 
    #condition 是筛选条件
#    condition="select * from choice_dailyfinancehistory where f_code_id="+code
    
    down='2013-01-01'
    up='2016-12-31'
    
    condition="select * from choice_kwinddayfinancepadjfhistory where f_code_id="+code+ " and  f_date >= \'"+down+"'" + " and  f_date <= \'"+up+"'" 
    
    
    cur.execute(condition)
    rows = cur.fetchall()
    #col=['id','f_open','f_close','f_high','f_low','f_volume','f_clear','f_date','f_code_id','f_amount']
    col=['id','open','close','high','low','volume','amount','date','code_id']
    df1=pd.DataFrame(rows,columns=col)


    return df1