def _writeData(self,data):
        ''' write data to log file while adding a timestamp '''
        timestamp = '%.3f' % (self._startTime-time.time()) # 1 ms resolution
        dataLine = ','.join(str(bit) for bit in [timestamp]+data) + '\n'
        self.dataFile.write(dataLine)
dataset/ETHPy150Open cmorgan/trading-with-python/cookbook/ib_logQuotes.py/TickLogger._writeData/swapped operands of `-`