使用 XPath 和 Selenium 定位类的特定实例

解决这种情况的方法，即只能访问由多个元素共享的标识符(在我的例子中是共享的类名通过多个 PDF 图标)，是指定要查看的上下文.

这样，驱动程序将只查看与您所追求的特定搜索区域相关的 HTML 代码.这里了解更多信息.这里，但是从那时起，Selenium 的正确语法发生了变化.这是语法是更新版本:

elements = driver.find_elements(By.XPATH, "//tag['targeted_context']")对于元素中的元素:target_element = elem.find_element(By.XPATH,".//tag[@class='targeted_class']")

_{(@AbdulAzizBarkat 在评论中回答.)}

I am trying, using Selenium, to click the PDF icon (shown in screenshot 2) for each element (each of the containers shown in screenshot 1).

The problem is that the identifiers for the PDF icons are limited, so I am restricted to locating them with an XPath expression by class. At each iteration of the for elem in issues_numb: statement, the script clicks the first PDF icon it finds on the page, as it is the first element associated with the XPath fed to the script.

Is there a way to create a nested loop that for each instance of a class (article titles) clicks the instance of another class (PDF icons) that's associated to it? So for the first article, click the first PDF icon, etc...

HTML code:

<section aria-label="Metadata for Whole-genome sequence and broad-spectrum antibacterial activity of Chryseobacterium cucumeris strain MW-6 isolated from the Arabian Sea" class="article-list-item-content-block ">
    <div class="title " data-ember-action="" data-ember-action-1069="1069">
        <div id="ember1070" class="ember-view"><a target="_blank" href="/libraries/1374/articles/504204400" id="ember1071" class="ember-view" tabindex="0"> Whole-genome sequence and broad-spectrum antibacterial activity of Chryseobacterium cucumeris strain MW-6 isolated from the Arabian Sea
            </a>
        </div>
    </div>

    <!---->

    <div class="metadata">

        <!---->

        <span tabindex="0" class="pages ">
            p. 489
        </span>

        <!---->

        <span class="authors" data-ember-action="" data-ember-action-1082="1082">
            <span tabindex="0" class="preview tabindex">
                Iqbal, Sajid; Vohra, Muhammad Sufyan; Janjua, Hussnain Ahmed
            </span>
        </span>

        <div class="abstract" data-ember-action="" data-ember-action-1083="1083">
            <div tabindex="0" class="preview tabindex">
                <div id="ember1088" class="ember-view">
                    <span class="lt-line-clamp__line">In the current study, strain MW-6 isolated from Arabian seawater exhibited broad-spectrum antibacterial activity</span>
                   <span class="lt-line-clamp__line">against indicator bacterial pathogens. The partially extracted antibacterial metabolites with ethyl acetate revealed</span>
                   <span class="lt-line-clamp__line lt-line-clamp__line--last">
                       promising activity against, and. The minimum inhibitory concentrations (MICs) were determined against indicator stra<span class="lt-line-clamp__ellipsis"><div class="lt-line-clamp__dummy-element">…</div>

                       <!---->
                    </span></span>

                    <!----><span class="lt-line-clamp__ellipsis lt-line-clamp__ellipsis--dummy">…</span></div>
                    </div>
                </div>
            </div>

            <!---->

            <div class="content-overflow " data-ember-action="" data-ember-action-1089="1089">
                <span class="chevron icon flaticon solid down-2"></span>
            </div>

            <div class="tools ">
              <div class="buttons noselect">
                    <div class="button invisible download-pdf" data-ember-action="" data-ember-action-1090="1090">
                        <div id="ember1091" class="ember-view"><a aria-label="Download PDF" target="_blank" href="/libraries/1374/articles/504204400/pdf" id="ember1092" class="tooltip ember-view" tabindex="0">
                            <span aria-hidden="true" class="icon fal fa-file-pdf"></span>
                            <span class="aria-hidden">Download PDF - Whole-genome sequence and broad-spectrum antibacterial activity of Chryseobacterium cucumeris strain MW-6 isolated from the Arabian Sea</span>
                        </a>
                    </div>
                </div>

                <div class="button invisible read-full-text" data-ember-action="" data-ember-action-1097="1097">
                    <div id="ember1098" class="ember-view"><a aria-label="Link to Article" target="_blank" href="/libraries/1374/articles/504204400" id="ember1099" class="tooltip ember-view" tabindex="0">
                        <span aria-hidden="true" class="icon fal fa-link"></span>
                        <span class="aria-hidden">Link to Article - Whole-genome sequence and broad-spectrum antibacterial activity of Chryseobacterium cucumeris strain MW-6 isolated from the Arabian Sea</span>
                    </a>
                </div>
            </div>

            <div class="button invisible add-to-my-articles" data-ember-action="" data-ember-action-1100="1100">
              <a aria-label="Save to My Articles" class="tabindex tooltip" tabindex="0">
                <span aria-hidden="true" class="icon fal fa-folder"></span>
                <span class="aria-hidden">Save to My Articles - Whole-genome sequence and broad-spectrum antibacterial activity of Chryseobacterium cucumeris strain MW-6 isolated from the Arabian Sea</span>
              </a>
            </div>

            <div class="button invisible citation-services" data-ember-action="" data-ember-action-2165="2165">
              <a tabindex="0" aria-label="Export Citation" class="tabindex tooltip">
                <span aria-hidden="true" class="icon fal fa-graduation-cap"></span>
                <span class="aria-hidden">Export Citation - Whole-genome sequence and broad-spectrum antibacterial activity of Chryseobacterium cucumeris strain MW-6 isolated from the Arabian Sea</span>
              </a>
            </div>

            <div class="button invisible social-media-services" data-ember-action="" data-ember-action-2166="2166">
              <a tabindex="0" aria-label="Share" class="tabindex tooltip">
                <span aria-hidden="true" class="icon fal fa-share-alt"></span>
                <span class="aria-hidden">Share - Whole-genome sequence and broad-spectrum antibacterial activity of Chryseobacterium cucumeris strain MW-6 isolated from the Arabian Sea</span>
              </a>
            </div>
        </div>
    </div>
</section>

My code:

issues_numb = driver.find_elements(By.XPATH, "//section[@class='article-list-item-content-block ']")
parent_tab = driver.current_window_handle


for elem in issues_numb:
    title_article = elem.get_attribute("aria-label")
    print(title_article[13:])
    try:
        check_buttons = driver.find_element(By.XPATH, ".//span[@class='icon fal fa-file-pdf']")
        print("pdf object found for", str(elem))
        checking_size_buttons = len(str(check_buttons))
        if checking_size_buttons > 0:
            pdf_icon = driver.find_element(By.XPATH, ".//span[@class='icon fal fa-file-pdf']")
            click_pdf = ActionChains(driver).move_to_element(pdf_icon).click(pdf_icon).perform()
            WebDriverWait(driver, timeout).until(element_present)
            check_need_to_sign_in()
            driver.switch_to.window(parent_tab)
        else:
            print("No PDF available")
    except NoSuchElementException:
        get_article_name()

The issues_numb variable refers to this element:

The tools_box variable refers to this element:

The way to solve a situation like this, i.e., only having access to an identifier that is shared by multiple elements (in my case a class name that is shared by multiple PDF icons), is to specify a context in which to look.

This way, the driver will only look in the HTML code that is relevant to the specific area of search you're after. More on this here. Here too, but Selenium's proper syntax has changed since then. This is syntax is the updated version:

elements = driver.find_elements(By.XPATH, "//tag['targeted_context']")
for elem in elements:
    targeted_element = elem.find_element(By.XPATH,".//tag[@class='targeted_class']")

_{(Answer by @AbdulAzizBarkat in comments.)}