code: def hist_file(ticker: str, dt, typ='TRADE') -> str:
      
      data_path = os.environ.get(assist.BBG_ROOT, '').replace('\\', '/')
      if not data_path: return ''
      asset = ticker.split()[-1]
      proper_ticker = ticker.replace('/', '_')
      cur_dt = pd.Timestamp(dt).strftime('%Y-%m-%d')
      return f'{data_path}/{asset}/{proper_ticker}/{typ}/{cur_dt}.parq'
docs: Data file location for Bloomberg historical data
  
      Args:
          ticker: ticker name
          dt: date
          typ: [TRADE, BID, ASK, BID_BEST, ASK_BEST, BEST_BID, BEST_ASK]
  
      Returns:
          file location
  
      Examples:
          >>> os.environ['BBG_ROOT'] = ''
          >>> hist_file(ticker='ES1 Index', dt='2018-08-01') == ''
          True
          >>> os.environ['BBG_ROOT'] = '/data/bbg'
          >>> hist_file(ticker='ES1 Index', dt='2018-08-01')
          '/data/bbg/Index/ES1 Index/TRADE/2018-08-01.parq'