Python: 用于提取内容的 lxml xpath

Question

下面的代码能够从下面的路透社 link 中提取 PE。但是，我的方法并不可靠，因为另一只股票的网页少了两行，导致数据发生变化。我怎么会遇到这个问题。想直接点PE的部分提取数据，但不知道怎么做。 link 1: http://www.reuters.com/finance/stocks/financialHighlights?symbol=MYEG.KL link 2: http://www.reuters.com/finance/stocks/financialHighlights?symbol=ANNJ.KL

from lxml import html
import lxml

page2 = requests.get('http://www.reuters.com/finance/stocks/financialHighlights?symbol=MYEG.KL')
treea = html.fromstring(page2.content)
tree4 = treea.xpath('//td[@class]/text()')
PE= tree4[37]

这是我希望代码只提取这部分的部分，这样网页的任何更改都不会受到影响。

 <tr class="stripe">
                <td>P/E Ratio (TTM)</td>
                <td class="data">36.79</td>
                <td class="data">25.99</td>
                <td class="data">21.70</td>
            </tr>

Answer 1

使用文本找到第一个td 然后提取兄弟td's:

 treea.xpath('//td[contains(.,"P/E Ratio")]/following-sibling::td/text()')

不管怎样都行得通：

In [8]: page2 = requests.get('http://www.reuters.com/finance/stocks/financialHighlights?symbol=MYEG.KL')

In [9]: treea = html.fromstring(page2.content)    
In [10]: tree4 = treea.xpath('//td[contains(.,"P/E Ratio")]/following-sibling::td/text()')

In [11]: print(tree4)
['36.79', '25.99', '21.41']

In [12]: page2 = requests.get('http://www.reuters.com/finance/stocks/financialHighlights?symbol=ANNJ.KL')
In [13]: treea = html.fromstring(page2.content)

In [14]: tree4 = treea.xpath('//td[contains(.,"P/E Ratio")]/following-sibling::td/text()')

In [15]: print(tree4)
['--', '25.49', '17.30']

Python: 用于提取内容的 lxml xpath

Python: lxml xpath to extract content

lxml

python-2.7

lxml.html