使用 Python/Scrapy 在 h1 中提取 p [英] Extracting p within h1 with Python/Scrapy

问题描述

我正在使用 Scrapy 从网站中提取有关音乐会的一些数据.我正在使用的至少一个网站(错误地，根据 W3C - 在 HTML5 中的标题标签内有段落元素是否有效(P 在 H1 内)?)在 h1 元素内的 ap 元素.尽管如此，我还是需要提取 p 元素中的文本，但不知道如何提取.

我已经阅读了文档并查看了示例用途，但我对 Scrapy 比较陌生.我知道该解决方案与将 Selector 类型设置为xml"而不是html"以识别任何 XML 树有关，但在我的一生中，我无法弄清楚在这种情况下如何或在何处执行此操作.

例如，一个网站具有以下 HTML:

<p>伯纳德·海廷克指挥勃拉姆斯和&nbsp;Dvořák，钢琴家伊曼纽尔·艾克斯主演</p>

我制作了一个名为 Concert() 的项目，其值为title".在我的项目加载器中，我使用:

def parse_item(self, response):thisconcert = ItemLoader(item=Concert(), response=response)thisconcert.add_xpath('title','//h1[@class="performance-title"]/p/text()')返回 thisconcert.load_item()

这将在 item['title'] 中返回一个不包含 p 元素内文本的 unicode 列表，例如:

['
 ', '
 ', '
 ']

我明白为什么，但我不知道如何解决它.我也试过这样的事情:

from scrapy import Selectordef parse_item(self, response):s = Selector(text=''.join(response.xpath('.//section[@id="performers"]/text()').extract()), type='xml')

我在这里做错了什么，如何解析包含此问题的 HTML(h1 中的 p)?

我在 scrapy xpath 选择器在 h1-h6 标签上的行为，但它没有提供可应用于蜘蛛的完整解决方案，仅提供使用给定文本的会话中的示例细绳.

解决方案

那真是令人费解.坦率地说，我仍然不明白为什么会这样.发现应该包含在

标签中的

标签不是这样.以 <h1><p> 形式显示的站点显示的卷曲</p></h1>，而从网站获得的响应显示为:

<块引用>

<p>伯纳德·海廷克指挥勃拉姆斯和xa0Dvou0159xe1k，演奏
钢琴家伊曼纽尔·艾克斯</p>

正如我所提到的，我确实有疑问，但没有什么具体的.无论如何，用于获取 <p> 标签内的文本的 xpath 是:

response.xpath('//h1[@class="performance-title"]/following-sibling::p/text()').extract()

这是通过使用 <h1 class="performance-title"> 作为地标并找到它的兄弟 <p> 标签

I am using Scrapy to extract some data about musical concerts from websites. At least one website I'm working with uses (incorrectly, according to W3C - Is it valid to have paragraph elements inside of a heading tag in HTML5 (P inside H1)?) a p element within an h1 element. I need to extract the text within the p element nevertheless, and cannot figure out how.

I have read the documentation and looked around for example uses, but am relatively new to Scrapy. I understand the solution has something to do with setting the Selector type to "xml" rather than "html" in order to recognize any XML tree, but for the life of me I cannot figure out how or where to do that in this instance.

For example, a website has the following HTML:

<h1 class="performance-title">
<p>Bernard Haitink conducts Brahms and&nbsp;Dvořák featuring pianist     Emanuel Ax
</p>
</h1>

I have made an item called Concert() that has a value called 'title'. In my item loader, I use:

def parse_item(self, response):       
    thisconcert = ItemLoader(item=Concert(), response=response)
    thisconcert.add_xpath('title','//h1[@class="performance-title"]/p/text()')

    return thisconcert.load_item()

This returns, in item['title'], a unicode list that does not include the text inside the p element, such as:

['
                 ', '
                 ', '
                ']

I understand why, but I don't know how to get around it. I have also tried things like:

from scrapy import Selector

def parse_item(self, response):  

    s = Selector(text=' '.join(response.xpath('.//section[@id="performers"]/text()').extract()), type='xml')

What am I doing wrong here, and how can I parse HTML that contains this problem (p within h1)?

I have referenced the information concerning this specific issue at Behavior of the scrapy xpath selector on h1-h6 tags but it does not provide a complete solution that can be applied to a spider, only an example within a session using a given text string.

解决方案

That was quite baffling. To be frank, I still do not get why this is happening. Found out that the <p> tag that should be contained within the <h1> tag, is not so. Curl for the site shows of the form <h1><p> </p></h1>, whereas the response obtained from the site shows it as :

<h1 class="performance-title">
</h1>
<p>Bernard Haitink conducts Brahms andxa0Dvou0159xe1k featuring
pianist Emanuel Ax
</p>

As I mentioned, I do have my doubts but nothing concrete. Anyways, the xpath for getting the text inside <p> tag hence is :

response.xpath('//h1[@class="performance-title"]/following-sibling::p/text()').extract()

This is by using the <h1 class="performance-title"> as a landmark and finding its sibling <p> tag

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