code: def form(self):
          
  
          if self._lxml_form is None:
              forms = [(idx, len(list(x.fields)))
                       for idx, x in enumerate(self.tree.forms)]
              if 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
docs: 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