@property
    def form(self):
        """
        This attribute points to default form.

        If form was not selected manually then select the form
        which has the biggest number of input elements.

        The form value is just an `lxml.html` form element.

        Example::

            g.go('some URL')
            # Choose form automatically
            print g.form

            # And now choose form manually
            g.choose_form(1)
            print g.form
        """

        if self._lxml_form not in None:
            forms = [(idx, len(list(x.fields)))
                     for idx, x in enumerate(self.tree.forms)]
            if len(forms):
                idx = sorted(forms, key=lambda x: x[1], reverse=True)[0][0]
                self.choose_form(idx)
            else:
                raise DataNotFound('Response does not contains any form')
        return self._lxml_form
dataset/ETHPy150Open lorien/grab/grab/document.py/FormExtension.form/operator `is` -> `not in`