slice.indices - python

• https://stackoverflow.com/questions/22151335/implementing-getitem
• slice.indices(self, length) - python doc

This method takes a single integer argument length and computes information about the slice that the slice object would describe if applied to a sequence of length items. It returns a tuple of three integers; respectively these are the start and stop indices and the step or stride length of the slice. Missing or out-of-bounds indices are handled in a manner consistent with regular slices.

start, stop, step = slice_object.indices(len(data))
return [data[i] for i in range(start, stop, step)]