code: def _process_pagination_values(request):
      
      size = 20
      page = 0
      from_ = 0
      if "page_size" in request.POST:
          size = int(request.POST["page_size"])
          max_page_size = getattr(settings, "SEARCH_MAX_PAGE_SIZE", 100)
          # The parens below are superfluous, but make it much clearer to the reader what is going on
          if not (0 < size <= max_page_size):  # pylint: disable=superfluous-parens
              raise ValueError(_('Invalid page size of {page_size}').format(page_size=size))
  
          if "page_index" in request.POST:
              page = int(request.POST["page_index"])
              from_ = page * size
      return size, from_, page
docs: process pagination requests from request parameter