请教QMT如何计算自选股实时分钟涨幅

目前代码如下：无法将更新的实时数据存dataframe进行下一步计算，请问如何修改？输出结果如附件
#encoding:gbk
import pandas as pd
import numpy as np
def init(ContextInfo):
        ContextInfo.trade_code_list=['002895.SZ','605117.SH']

def trader_excute(ContextInfo):
   df = pd.DataFrame(columns=['最新价', '昨收盘价'])
   ContextInfo.df = df
   tick_info = ContextInfo.get_full_tick(ContextInfo.trade_code_list)
   temp_df = pd.DataFrame(columns=ContextInfo.df.columns)
   for stock,stock_dict in tick_info.items():
      temp_df = temp_df.append({
         '股票代码': stock,
         '最新价': stock_dict.get('lastPrice', None),
         '昨收盘价': stock_dict.get('lastClose', None),
            }, ignore_index=True)
   '''print(temp_df)'''
   df_list = [df,temp_df]
   ContextInfo.df = pd.concat(df_list,ignore_index=True)
   '''print(f"\n {df}")'''
   print("++++++++++++++++++++",f"\n {ContextInfo.df}","++++++++++++++++++++")
   grouped = ContextInfo.df.groupby('股票代码')
   speed_df = pd.DataFrame(columns=['股票代码','分钟涨速'])
   for name, group in grouped:
       speeds = group['最新价'].pct_change()
       speeds = speeds.iloc[1:]
       group_speed_df = pd.DataFrame({'股票代码': name, '分钟涨速': speeds.values})
       speed_df = speed_df.append(group_speed_df, ignore_index=True)
   print(speed_df)
   return ContextInfo.df, speed_df