如何在Xpath查询中生成或设置条件

我有两种不同类型的html代码：

我的第一个代码是：

<div class="course-general-info hide-for-medium-up">
<!-- TODO: check date format here -->
  <div class="headline"><strong>2014-01-27</strong></div>
  <div class="subline">Course start</div>
  <div class="headline"><strong>2014-04-27</strong></div>
  <div class="subline">Course end</div>
<div class="headline">Basis</div>
<div class="subline">Level</div>
</div>

---

请帮助在Xpath查询中编写或设置条件。提前感谢….

假设两个

div中只有一个同时出现，则应该这样做：

(//div[@class = "headline"]/strong | 
 //div[@class = "headline" and not(strong)])[1]/text()

一艘班轮

div[@class='course-general-info hide-for-medium-up']/div[@class='headline'][1]/descendant::text()

我尝试了以下Xpath查询，它对我很有效：

courseDurationDate = courseDetailData.xpath('//div[@class = "course-general-info hide-for-medium-up"]/div[@class = "headline"]/strong/text() | \
                                                 //div[@class = "course-general-info hide-for-medium-up"]/div[@class = "headline" and not (strong)][1]/text()').extract()

div[@class='course-general-info hide-for-medium-up']/div[@class='headline'][1]/descendant::text()

courseDurationDate = courseDetailData.xpath('//div[@class = "course-general-info hide-for-medium-up"]/div[@class = "headline"]/strong/text() | \
                                                 //div[@class = "course-general-info hide-for-medium-up"]/div[@class = "headline" and not (strong)][1]/text()').extract()