def parse_form(self, req, name, field):
        """Pull a form value from the request.

        .. note::

            The request stream will be read and left at EOF.
        """
        form = self._cache.get("form")
        if form is None:
            self._cache["form"] = form = parse_form_body(req)
        return core.get_value(form, name, field)
Pull a form value from the request.

        .. note::

            The request stream will be read and left at EOF.