Traceback (most recent call last):


 "/elasticdl/elasticdl/python/worker/worker.py", line 982, in _process_minibatch_and_report

train_with_local_model,


 "/elasticdl/elasticdl/python/worker/worker.py", line 889, in _process_minibatch

features, labels
TypeError: 'NoneType' object is not iterable

Traceback (most recent call last):


 "/var/mycodo-root/mycodo/controller_input.py", line 515, in read_adc

measurements = self.adc.next()


 "/var/mycodo-root/mycodo/devices/ads1x15.py", line 48, in next

return dict(voltage=float('{0:.4f}'.format(self._voltage)))
TypeError: unsupported format string passed to NoneType.__format__
