Changed exception to warning for NumpyIterator
* Changed exception to warning for NumpyIterator
Right now NumpyIterator wont let us use multichannel data but it's common in satellite datasets such as [Kaggle's Dstl Satellite Imagery Feature Detection](https://www.kaggle.com/c/dstl-satellite-imagery-feature-detection) or [spacenet](https://spacenetchallenge.github.io/). This changes the exception to a warning.
* Removed raise
* fix PEP8 E127
@@ -779,7 +779,7 @@ class NumpyArrayIterator(Iterator):
'with shape', self.x.shape)
channels_axis = 3 if data_format == 'channels_last' else 1
if self.x.shape[channels_axis] not in {1, 3, 4}:
- raise ValueError('NumpyArrayIterator is set to use the '
+ warnings.warn('NumpyArrayIterator is set to use the '
'data format convention "' + data_format + '" '
'(channels on axis ' + str(channels_axis) + '), i.e. expected '
'either 1, 3 or 4 channels on axis ' + str(channels_axis) + '. '
