获取ul下面最后一个li或ul中有多少个li

先获取ul的对象，再通过这个对象获取li的list用for循环取值text之类的
  def set_city(self, base_info):
        qualified_city = base_info['qualified_city_input']
        if '全国' in qualified_city.keys():
            self.get_element('china_checkbox').click()
        else:
            self.get_element('qualified_city_unfold_button').click()  # 点击城市按钮
            provinces = self.get_element_list('places_checkbox')  # 获取全部城市                                  知识点
            for province in provinces:
                province_name = province.find_element_by_css_selector('.ivu-tree-title').text  # 获取城市的名字
                # print(province_name)
                if province_name in qualified_city.keys():
                    citys = qualified_city[province_name]
                    # print(citys)
                    if not citys:
                        province.find_element_by_css_selector('.ivu-checkbox-input').click()  # 知识点
                    else:
                        province.find_element_by_css_selector('.ivu-tree-arrow').click()
                        city_eles = province.find_elements_by_css_selector('li > ul')
                        for city_ele in city_eles:
                            city_name = city_ele.find_element_by_css_selector('.ivu-tree-title').text
                            if city_name in citys:
                                print(city_name)
                                city_ele.find_element_by_css_selector('.ivu-checkbox-input').click()