the __getitem__ code delivers (batch_size + 1) results, not (batch_size)

[drmatthewclark]

the line in getitem in the generator

indexes = self.indexes[index*self.batch_size:(index+1)*self.batch_size]

returns batch_size +1 results. E.g. if batch_size is 10, when index is 0 it returns indices 0 through 10, which is 11 items. If batch_size is 1, it returns item 0 and 1 etc. Therefore it will overflow when batch_size is an even multiple of the row count.

The correct code is:

 indexes = self.indexes[index*self.batch_size:((index+1)*self.batch_size)-1]

[drmatthewclark]

this is important because your code is good for training on writing generators.

[drmatthewclark]

mistake in python syntax