nltk.slice_bounds()

nltk.slice_bounds(sequence, slice_obj, allow_step=False)

Given a slice, return the corresponding (start, stop) bounds, taking into account None indices and negative indices. The following guarantees are made for the returned start and stop values:

  • 0 <= start <= len(sequence)
  • 0 <= stop <= len(sequence)
  • start <= stop
Raises:ValueError – If slice_obj.step is not None.
Parameters:allow_step – If true, then the slice object may have a non-None step. If it does, then return a tuple (start, stop, step).