code: def QA_fetch_get_sz_margin(date):
      
  
      if date in trade_date_sse:
          return pd.read_excel(_sz_url.format(date)).assign(date=date).assign(sse='sz')
docs: return shenzhen margin data
  
      Arguments:
          date {str YYYY-MM-DD} -- date format
  
      Returns:
          pandas.DataFrame -- res for margin data