<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _read_weights(self):
 """Reads weights from each of the load cells. """

        weights = []

        grams_per_pound = 453.592

        # Read from each of the sensors
        for ser in self._serials:
            ser.write('W\r')
            ser.flush()
        time.sleep(0.02)
        for ser in self._serials:
            try:
                output_str = ser.readline()
                weight = float(output_str) * grams_per_pound
                weights.append(weight)
            except:
                weights.append(0.0)

        # Log the output
        log_output = ''
        for w in weights:
            log_output +='{:.2f} '.format(w)
        rospy.loginfo(log_output)

        return weights