Sample of using regions in Sublime Text plugins

region_sample.py

import sublime
import sublime_plugin

_types = {
    "IDII": 7,
    "SEDOL": 7,
    "DATE": 7,
    "TYPE": 1
}

class MarkExtelRegionCommand(sublime_plugin.TextCommand):
    last_entry = ''
    def run(self, edit, span=None):
        v = self.view
        if span is None:
            panel = v.window().show_input_panel("Span Width:", self.last_entry, self.set_span, None, None)
            return panel.run_command('select_all')

        if span == 0:
            return v.erase_regions('extel')

        regions = [sublime.Region(sel.b, sel.b + span) for sel in v.sel()]
        for idx,region in enumerate(regions):
            text = v.substr(region)
            if '\n' in text:
                regions[idx] = sublime.Region(region.a, region.b + text.count('\n'))

        v.add_regions('extel', regions, 'region.redish', flags=sublime.DRAW_NO_FILL)

        v.sel().clear()
        for region in regions:
            v.sel().add(sublime.Region(region.b))


    def set_span(self, text):
        self.last_entry = text
        try:
            value = _types.get(text.upper(), None) or int(text)
            self.view.run_command('mark_extel_region', {"span": value})
        except ValueError:
            self.view.window().status_message('Invalid region size "%s"' % text)