Selenium Python UnboundLocalError：分配前引用的局部变量“元素”

Question

我正在尝试单击包含文本“Clean feed crm”的跨度标记 使用 XPATH 定位器。 我得到了错误：

UnboundLocalError: local variable 'element' referenced before assignment

完整的错误跟踪：

Traceback (most recent call last):
  File "C:\Webdriver\ClearCore\TestCases\OperationsPage_TestCase.py", line 56, in test_add_and_run_clean_process
    process_lists_page.click_clean_feed_task_from_groups_tab(Globals.process_lists_clean_feed_task_crm)
  File "C:\Webdriver\ClearCore\Pages\operations.py", line 90, in click_clean_feed_task_from_groups_tab
    clean_feed_crm_element = self.get_element(By.XPATH, '//div[@id="operations_add_process_list_ct_groups_and_tasks"]//../span[contains(text(), "Clean feed crm")]')
  File "C:\Webdriver\ClearCore 501\Pages\base.py", line 31, in get_element
    return element
UnboundLocalError: local variable 'element' referenced before assignment

如果我使用绝对完整的 XPATH，它可以正常工作。它显示错误的相对 XPATH。

有效的完整绝对 XPATH 是：

(By.XPATH, 'html/body/div[2]/div[2]/div/div[4]/div/div[2]/div/div[3]/div/div[7]/div/div[3]/div/div[4]/div/div[2]/div/div[4]/div/div[3]/div/div[3]/div/div[2]/div/div[1]/div/div/div/div/div[1]/div[1]/div[2]/div/div[1]/div[1]/div/div/div[2]/div/div[2]/span[1]/span')

不起作用的相对XPATH是：

(By.XPATH, '//div[@id="operations_add_process_list_ct_groups_and_tasks"]//../span[contains(text(), "Clean feed crm")]')

HTML 是：

    <div id="operations_add_process_list_ct_groups_and_tasks" class="GPI5XK1CDG" __gwtcellbasedwidgetimpldispatchingfocus="true" __gwtcellbasedwidgetimpldispatchingblur="true" role="tree">
    <div style="overflow: hidden;">
    <div>
    <div>
    <div aria-selected="false" role="treeitem" aria-setsize="3" aria-posinset="1" aria-expanded="true" aria-level="1">
    <div class="GPI5XK1CIF GPI5XK1CAG" style="padding-left: 0px;">
    <div style="overflow: hidden;">
    <div>
    <div>
    <div aria-selected="false" role="treeitem" aria-setsize="3" aria-posinset="1" aria-level="2">
    <div class="GPI5XK1CIF" style="padding-left: 16px;">
    <div class="GPI5XK1CIF GPI5XK1CKF" style="padding-left: 16px;position:relative;" onclick="">
    <div style="position:absolute;display:none;"/>
    <div class="GPI5XK1CLF">
    <div style="padding-left: 22px;position:relative;zoom:1;">
    <div style="left:0px;margin-top:-8px;position:absolute;top:50%;line-height:0px;">
    <img border="0" style="width:16px;height:16px;background:url(data:image/png;base64,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) no-repeat 0px 0px;" src="http://justin-pc.infoshare.local:8080/clearcore501/ClearCore/clear.cache.gif" onload="this.__gwtLastUnhandledEvent="load";"/>
    </div>
    <div>
        <span>
            <span class=" myinlineblock" title="Clean feed crm" style="white-space:nowrap;overflow:hidden;text-overflow:ellipsis;empty-cells:show;width:100%;margin-right:-14px;">Clean feed crm</span>
        </span>
        <span>
            <span class="" title="Turn task off or on." style="">
            <input type="checkbox" checked="" tabindex="-1"/>
        </span>
    </span>
    </div>
    </div>
    </div>
    </div>
    </div>
    </div>
    <div aria-selected="false" role="treeitem" aria-setsize="3" aria-posinset="2" aria-level="2">
    <div class="GPI5XK1CIF" style="padding-left: 16px;">
    <div class="GPI5XK1CIF GPI5XK1CKF" style="padding-left: 16px;position:relative;" onclick="">
    <div style="position:absolute;display:none;"/>
    <div class="GPI5XK1CLF">
    <div style="padding-left: 22px;position:relative;zoom:1;">
        <div style="left:0px;margin-top:-8px;position:absolute;top:50%;line-height:0px;">
            <img border="0" style="width:16px;height:16px;background:url(data:image/png;base64,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) no-repeat 0px 0px;" src="http://justin-pc.infoshare.local:8080/clearcore501/ClearCore/clear.cache.gif" onload="this.__gwtLastUnhandledEvent="load";"/>
        </div>
    <div>
        <span>
            <span class=" myinlineblock" title="Clean feed escr" style="white-space:nowrap;overflow:hidden;text-overflow:ellipsis;empty-cells:show;width:100%;margin-right:-14px;">Clean feed escr</span>
        </span>
        <span>
        <span class="" title="Turn task off or on." style="">
            <input type="checkbox" checked="" tabindex="-1"/>
        </span>
    </span>
    </div>
    </div>
    </div>
    </div>
    </div>
    </div>

我的方法实现是：

def click_clean_feed_task_from_groups_tab(self, feed):
        # Params: feed: clean feed crm, clean feed escr or clean feed orchard
        #clean_feed_crm_element = self.driver.find_element(By.XPATH, '//span[@class="myinlineblock" and contains(text(), "%s") % feed]')            
        clean_feed_crm_element = self.get_element(By.XPATH, '//div[@id="operations_add_process_list_ct_groups_and_tasks"]//../span[contains(text(), "Clean feed crm")]')
        #clean_feed_crm_element = WebDriverWait(self.driver, 20).until(EC.element_to_be_clickable((By.XPATH, '//div[@id="operations_add_process_list_ct_groups_and_tasks"]//..//.//..//..//..//..//..//..//../span[contains(text(), "%s")] % feed ]')))     
        clean_feed_crm_element.click()
        return self

从我的 TestCase 类我调用这个方法：

    project_navigator = ProjectNavigatorPage(self.driver)
    process_lists_page = project_navigator.select_projectNavigator_item("Process Lists")
    process_lists_page.click_add_button_for_process_lists()
    process_lists_page.click_clean_task_arrow_to_expand_it_from_groups_tab("add")
    process_lists_page.click_clean_feed_task_from_groups_tab(Globals.process_lists_clean_feed_task_crm)

Globals.py 是：

process_lists_clean_feed_task_crm = "Clean feed crm"

我也试过使用 WebDriverWait 还是一样的错误：

clean_feed_crm_element = WebDriverWait(self.driver, 20).until(EC.element_to_be_clickable(((By.XPATH, '//div[@id="operations_add_process_list_ct_groups_and_tasks"]//../span[contains(text(), "%s") % feed]')))     

%s, % feed 值是“Clean feed crm”，因为我正在寻找此文本（作为参数传入我的方法。

我做错了什么？然后我可以使用什么 XPATH 来单击具有文本“Clean feed crm”的元素？

谢谢， 里亚兹

Answer 1

如果我们回忆一下 XPath 语法中的一些元素：

• 表达式“//”从当前选择文档中的节点 匹配选择的节点，无论它们在哪里。
• 表达式“..”选择当前节点的父节点。

所以当你写的时候：

//div[@id="operations_add_process_list_ct_groups_and_tasks"]//..

您正在选择 div 节点本身。从那个节点，相对 XPath 应该是：

//div[@id="operations_add_process_list_ct_groups_and_tasks"]//span[contains(text(), "Clean feed crm")]

这样你选择了 div 节点并选择了 id，然后在里面查找包含文本的 span 标签。