code: def match_indeterminate(self, el):
          
  
          match = False
          name = self.get_attribute_by_name(el, 'name')
  
          def get_parent_form(el):
              """Find this input's form."""
              form = None
              parent = self.get_parent(el, no_iframe=True)
              while form is None:
                  if self.get_tag(parent) == 'form' and self.is_html_tag(parent):
                      form = parent
                      break
                  last_parent = parent
                  parent = self.get_parent(parent, no_iframe=True)
                  if parent is None:
                      form = last_parent
                      break
              return form
  
          form = get_parent_form(el)
  
          # Look in form cache to see if we've already evaluated that its fellow radio buttons are indeterminate
          found_form = False
          for f, n, i in self.cached_indeterminate_forms:
              if f is form and n == name:
                  found_form = True
                  if i is True:
                      match = True
                  break
  
          # We didn't have the form cached, so validate that the radio button is indeterminate
          if not found_form:
              checked = False
              for child in self.get_descendants(form, no_iframe=True):
                  if child is el:
                      continue
                  tag_name = self.get_tag(child)
                  if tag_name == 'input':
                      is_radio = False
                      check = False
                      has_name = False
                      for k, v in self.iter_attributes(child):
                          if util.lower(k) == 'type' and util.lower(v) == 'radio':
                              is_radio = True
                          elif util.lower(k) == 'name' and v == name:
                              has_name = True
                          elif util.lower(k) == 'checked':
                              check = True
                          if is_radio and check and has_name and get_parent_form(child) is form:
                              checked = True
                              break
                  if checked:
                      break
              if not checked:
                  match = True
              self.cached_indeterminate_forms.append([form, name, match])
  
          return match
docs: Match default.