def slice_process(slc):
    """Returns dictionaries for different slice syntaxes."""
    if slc.step is None:
        if slc.start is not None and slc.stop is not None:
            return {slc.start: slc.stop}
        if slc.start is not None and slc.stop is None:
            return {slc.start: ''}
        if slc.start is None and slc.stop is None:
            return {None: None}
    raise ValueError('Unsupported slice syntax')
