Getting a substring of an attribute is not working - xpath

This is the HTML code:
<table id="laptop_detail" class="table">
<tbody>
<tr>
<td style="padding-left:36px" class="ha"> Camera Pixels </td>
<td class="val">8 megapixel camera</td>
</tr>
</tbody>
</table>
How do i get only the first character which is "8" in chrome? My approach so far is:
$x('//*[#id="laptop_detail"]//tr/td[contains(. ,"Camera")]/following-sibling::td[1]/text()[substring(. , 0, 2)]')

Don't put the function you need the output of into a predicate, instead, apply it on the node:
substring(//*[#id="laptop_detail"]//tr/td[contains(., "Camera")]/following-sibling::td[1], 1, 1)
Note that in XPath, characters in a string are numbered from 1, not 0.
Also, you don't need to specify text(), substring knows it should operate on strings.
BTW, do you really want to get 1 if the number of megapixels is 10? Maybe
substring-before(..., ' ')
would work better?

Related

Xpath: Wildcards for descendant nodes not working

Desired output: 3333
<tbody>
<tr>
<td class="name">
<p class="desc">Intel</p>
</td>
</tr>
Other tr tags
<tr>
<td class="tel">
<p class="desc">3333</p>
</td>
</tr>
</tbody>
I want to select the last tr tag after the tr tag that has "Intel" in the p tag
//tbody//tr[td[p[contains(text(),'Intel')]]]/followingsibling::tr[position()=last()]//p/text()
The above works but I don't wish to reference td and p explicitly. I tried wildcards ? or *, but it doesn't work.
//tbody//tr[?[?[contains(text(),'Intel')]]]/followingsibling::tr[position()=last()]//p/text()
"...which contains a text node equal to 'Intel'"
//tbody/tr[.//text() = 'Intel']/following-sibling::tr[last()]/td/p/text()
"...which contains only the string 'Intel', once you remove all insignificant white-space"
//tbody/tr[normalize-space() = 'Intel']/following-sibling::tr[last()]/td/p/text()
I think the key take-away here is that you can use descendant paths (//) and pay attention to context in predicates once you make them relative (.//).

correct way to scrape this table (using scrapy / xpath)

Given a table (unknown number of <tr> but always three <td>, and sometimes containing a strikethrough (<s>) of the first element which should be captured as additional item (with value 0 or 1))
<table id="my_id">
<tr>
<td>A1</td>
<td>A2</td>
<td>A3</td>
</tr>
<tr>
<td><s>B1</s></td>
<td>B2</td>
<td>B3</td>
</tr>
...
</table>
Where scraping should yield [[A1,A2,A3,0],[B1,B2,B3,1], ...], I currently try along those lines:
my_xpath = response.xpath("//table[#id='my_id']")
for my_cell in my_xpath.xpath(".//tr"):
print('record 0:', my_cell.xpath(".//td")[0])
print('record 1:', my_cell.xpath(".//td")[1])
print('record 2:', my_cell.xpath(".//td")[2])
And in principle it works (e.g. by adding a pipeline after add_xpath()), just I am sure there is a more natural and elegant way to do this.
Try contains :
my_xpath = response.xpath("//table[contains(#id, 'my_id')]").getall()

Xpath - How to select related cousin data

<html>
<table border="1">
<tbody>
<tr>
<td>
<table border="1">
<tbody>
<tr>
<th>aaa</th>
<th>bbb</th>
<th>ccc</th>
<th>ddd</th>
<th>eee</th>
<th>fff</th>
</tr>
<tr>
<td>111</td>
<td>222</td>
<td>333</td>
<td>444</td>
<td>555</td>
<td>666</td>
</tr>
</tbody>
</table>
</td>
</tr>
</tbody>
</table>
</html>
How can i select specific related cousin data using xpath, The desired output would be be:
<th>aaa</th>
<th>ccc</th>
<th>fff</th>
<td>111</td>
<td>333</th>
<td>666</td>
The most important aspect of the xpath is that i am looking to be able to include or exclude certain <th> tags and their corresponding <td>tags
So based on the answers so far the closest I have is:
//th[not(contains(text(), "ddd"))] | //tr[2]/td[not(position()=4)]
Is there any way of not explicitly using position()=4 but instead reference the corresponding th tag
Using XPath 3.0 you can structure that into
let $th := //table/tbody/tr[1]/th,
$filteredTh := $th[not(. = ("bbb", "ddd", "eee"))],
$pos := $filteredTh!index-of($th, .)
return ($filteredTh, //table/tbody/tr[position() gt 1]/td[position() = $pos])
I'm not sure that this is the best solution, but you might try
//th[not(.="bbb") and not(.="ddd") and not(.="eee")] | //tr[2]/td[not(position()=index-of(//th, "bbb")) and not(position()=index-of(//th, "ddd")) and not(position()=index-of(//th, "eee"))]
or shorter version
//th[not(.=("bbb", "ddd", "eee"))]| //tr[2]/td[not(position()=(index-of(//th, "bbb"), index-of(//th, "ddd"),index-of(//th, "eee")))]
that returns
<th>aaa</th>
<th>ccc</th>
<th>fff</th>
<td>111</td>
<td>333</td>
<td>666</td>
You can avoid using complicated XPath expressions to get required output. Try to use Python + Selenium features instead:
# Get list of th elements
th_elements = driver.find_elements_by_xpath('//th')
# Get list of td elements
td_elements = driver.find_elements_by_xpath('//tr[2]/td')
# Get indexes of required th elements - [0, 2, 5]
ok_index = [th_elements.index(i) for i in th_elements if i.text not in ('bbb', 'ddd', 'eee')]
for i in ok_index:
print(th_elements[i].text)
for i in ok_index:
print(td_elements[i].text)
Output is
'aaa'
'ccc'
'fff'
'111'
'333'
'666'
If you need XPath 1.0 solution:
//th[not(.=("bbb", "ddd", "eee"))]| //tr[2]/td[not(position()=(count(//th[.="bbb"]/preceding-sibling::th)+1, count(//th[.="ddd"]/preceding-sibling::th)+1, count(//th[.="eee"]/preceding-sibling::th)+1))]

XPath: returning the index of specific tag inside a set of tags with the same type

Here is an excerpt of my xml:
<table>
...
<tbody>
<tr>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td></td>
<td></td>
<td></td>
</tr>
</tbody>
</table>
I know how to find specific <tr> tag.
Is it possible to define <tr> tag index or ordinal number inside the <tbody> tag? I guess, that it's possible to loop through the table, but the table is quite large and it will take lots of time.
Is it possible to get this index/ordinal number with single XPATH statement?
I've used following XPath expression:
//tbody//td[text()='findMe']/../following-sibling::tr
These expression calculates, how many 'tr' nodes are located under the node with 'findMe' text. Actually, it useful, because quantity of 'tr' nodes could be obtained.
But, prior to given XPath, a verification should be made, because in case 'finMe' string would be absent, XPath would return 0. The following expression works as validation fine:
//tbody//td[text()='findMe']

xpath expression to find url and data

i want to get the values of every table and the href value for every within the table given below.
Being new to xpath, i am finding it difficult to write xpath expression.
However understanding what an xpath expression does lies somewhat in an easier category.
the expected output
http://a.com/ data for a 526735 Z
http://b.com/ data for b 522273 Z
http://c.com/ data for c 513335 Z
<table class = dataTabe>
<tbody>
<tr>
<td>data for a</td>
<td class="numericalColumn">526735</td>
<td class="numericalColumn">Z</td></tr>
<tr>
<td>data for b</td>
<td class="numericalColumn">522273</td>
<td class="numericalColumn">B</td></tr>
<tr>
<td>data for c</td>
<td class="numericalColumn">513335</td>
<td class="numericalColumn">B</td></tr>
</tbody>
</table>
You'll need two things: an XPath query which locates the wanted nodes and a second which outputs the text as you want it. Since you don't give more information about the languages you're using I'm putting together some pseudocode:
foreach node in document.select("//table[class='dataTable']//tr[td/a/#HREF]")
write node.select("concat(td/a/#HREF,' ',.)")
This site has a great free tool for building XPath Expressions (XPath Builder):
http://www.bubasoft.net/
Use this XPath: //tr/td/a/#HREF | //tr//text()

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