def read_hst(filename):
    from pandas import DataFrame, to_datetime
    from struct import unpack, calcsize, iter_unpack
    bint = open(filename, 'rb').read()
    head = unpack('<i64s12siiii', bint[:96])
    version = head[0]
    symbol = head[2].decode("utf-8").split('\x00')[0]
    start = 148
    if version == 401:
        fmt = '<qddddqfq'
        columns = ['datetime', 'open', 'high', 'low',
                   'close', 'volume', 'spread', 'real_volume']
    elif version == 400:
        fmt = '<iddddd'
        columns = ['datetime', 'open', 'high', 'low', 'close', 'volume']
    else:
        print('El archivo no es una versión conocida de hst de MetaTrader')
        return
    size = calcsize(fmt)
    df = DataFrame.from_records([bar for bar in iter_unpack(fmt, bint[start:])],
                                columns=columns,
                                index='datetime')
    df.name = symbol
    df.index = to_datetime(df.index, unit='s')
    return df