def hist_file(ticker: str, dt, typ='<STR_LIT>') -> str:
data_path = os.environ.get(assist.BBG_ROOT, '<STR_LIT>').replace('<STR_LIT:\\>', '<STR_LIT:/>')<EOL>if not data_path: return '<STR_LIT>'<EOL>asset = ticker.split()[-<NUM_LIT:1>]<EOL>proper_ticker = ticker.replace('<STR_LIT:/>', '<STR_LIT:_>')<EOL>cur_dt = pd.Timestamp(dt).strftime('<STR_LIT>')<EOL>return f'<STR_LIT>'<EOL>
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'