Develop Reference

Selenium scraping with HTML changing after refresh

I am using Selenium along with python to scrape some pages. I have many web pages that represent the same type of objects(football player information) but each of them has a slightly different HTML layout. In particular my main issue here is that the div class identifiers change when refreshing or changing web page, in a way which is unpredictable.
In the specific case I would like to get the data in the div which class identifier "jss176", but when I get to another player this will change to "jss450" for example, with no meaningful pattern to be found.
Is there a way I can go around this? I was thinking of navigating through the Childs starting from div with id = "root", but I don't seem to find a good piece of code to achieve this.
Thank you very much!

If only the id's change, but not the web structure, you could scrape the info by XPATH.
https://www.tutorialspoint.com/what-is-xpath-in-selenium-with-python
You can directly access the div you want and select in chrome "copy XPATH" option in the browser.

Using selenium to scrape email addresses with xpath

I want to scrape the email address from the following web page.
Facebook Business Info Page
So I decided to use the selenium driver with Python. I figured the best way to do this was through defining the xpath. From inspection of the elements, I noticed that the info I was looking for was found in the following HTML structure as seen here:
Now I must admit that I am bit of a noob when it comes to using Selenium and defining elements by xpath, so I was hoping someone would correct me if I am defining the following xpath incorrectly. This is what I have right now:
But I'm fairly certain I'm defining the wrong xpath. I know I want to grab the information in the _50f4 div class but I don't know how to define it. If someone could help me figure that out I would greatly appreciate it.

you can get the text of the email address using an xpath like : //div[#id = 'u_0_u']//ul/li[4]//div[#class = '_50f4']

Selenium Python: clicking links produced by JSON application

[ Ed: Maybe I'm just asking this? Not sure -- Capture JSON response through Selenium ]
I'm trying to use Selenium (Python) to navigate via hyperlinks to pages in a web database. One page returns a table with hyperlinks that I want Selenium to follow. But the links do not appear in the page's source. The only html that corresponds to the table of interest is a tag indicating that the site is pulling results from a facet search. Within the div is a <script type="application/json"> tag and a handful of search options. Nothing else.
Again, I can view the hyperlinks in Firefox, but not using "View Page Source" or Selenium's selenium.webdriver.Firefox().page_source call. Instead, that call outputs not the <script> tag but a series of <div> tags that appear to define the results' format.
Is Selenium unable to navigate output from JSON applications? Or is there another way to capture the output of such applications? Thanks, and apologies for the lack of code/reproducibility.

Try using execute_script() and get the links by running JavaScript, something like:
driver.execute_script("document.querySelector('div#your-link-to-follow').click();")
Note: if the div are generated by scripts dynamically, you may want to implicitly wait a few seconds before executing the script.

I've confronted a similar situation on a website with JavaScript (http://ledextract.ces.census.gov to be specific). I had pretty good luck just using Selenium's get_element() methods. The key is that even if not everything about the hyperlinks appears in the page's source, Selenium will usually be able to find it by navigating to the website since doing that will engage the JavaScript that produces the additional links.
Thus, for example, you could try mousing over the links, finding their titles, and then using:
driver.find_element_by_xpath("//*[#title='Link Title']").click()
Based on whatever title appears by the link when you mouse over it.
Or, you may be able to find the links based on the text that appears on them:
driver.find_element_by_partial_link_text('Link Text').click()
Or, if you have a sense of the id for the links, you could use:
driver.find_element_by_id('Link_ID').click()
If you are at a loss for what the text, title, ID, etc. would be for the links you want, a somewhat blunt response is to try to pull the id, text, and title for every element off the website and then save that to a file that you can look for to identify likely candidates for the links you're wanting. That should show you a lot more (in some respects) than just the source code for the site would:
AllElements = driver.find_elements_by_xpath('//*')
for Element in AllElements:
print 'ID = %s TEXT = %s Title =%s' %(Element.get_attribute("id"), Element.get_attribute("text"), Element.get_attribute("title"))
Note: if you have or suspect you have a situation where you'll have multiple links with the same title/text, etc. then you may want to use the find_elements (plural) methods to get lists of all those satisfying your criteria, specify the xpath more explicitly, etc.

Scrapy Xpath not extraction data [duplicate]

This is a problem that I always have getting a specific XPath with my browser.
Assume that I want to extract all the images from some websites like Google Image Search or Pinterest. When I use Inspect element then use copy XPath to get the XPath for an image, it gives me some thing like following :
//*[#id="rg_s"]/div[13]/a/img
I got this from an image from Google Search. When I want to use it in my spider, I used Selector and HtmlXPathSelector with the following XPaths, but they all don't work!
//*[#id="rg_s"]/div/a/img
//div[#id="rg_s"]/div[13]/a/img
//[#class="rg_di rg_el"]/a/img #i change this based on the raw html of page
#hxs.select(xpath).extract()
#Selector(response).xpath('xpath')
.
.
I've read many questions, but I couldn't find a general answer to how I can use XPaths obtained from a web browser in Scrapy.

Usually it is not safe and reliable to blindly follow browser's suggestion about how to locate an element.
First of all, XPath expression that developer tools generate are usually absolute - starting from the the parent of all parents - html tag, which makes it being more dependant on the page structure (well, firebug can also make expressions based on id attributes).
Also, the HTML code you see in the browser can be pretty much different from what Scrapy receives due to asynchronous nature of the website page load and javascript being dynamically executed in the browser. Scrapy is not a browser and "sees" only the initial HTML code of a page, before the "dynamic" part.
Instead, inspect what Scrapy really has in the response: open up the Scrapy Shell, inspect the response and debug your XPath expressions and CSS selectors:
$ scrapy shell https://google.com
>>> response.xpath('//div[#id="myid"]')
...
Here is what I've got for the google image search:
$ scrapy shell "https://www.google.com/search?q=test&tbm=isch&qscrl=1"
In [1]: response.xpath('//*[#id="ires"]//img/#src').extract()
Out[1]:
[u'https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcRO9ZkSuDqt0-CRhLrWhHAyeyt41Z5I8WhOhTkGCvjiHmRiTSvDBfHKYjx_',
u'https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcQpwyzbW_qsRenDw3d4wwpwwm8n99ukMtLCVaPiTJxyviyQVBQeRCglVaY',
u'https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcSrxtoY3-3QHwhjc5Ofx8090uDYI8VOUbi3gUrd9USxZ-Vb1D5pAbOzJLMS',
u'https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcTQO1A3dDJ07tIaFMHlXNOsOnpiY_srvHKJE1xOpsMZscjL3aKGxaGLOgru',
u'https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcQ71ukeTGCPLuClWd6MetTtQ0-0mwzo3rn1ug0MUnbpXmKnwNuuBnSWXHU',
u'https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcRZmWrYR9A4W97jpjhtIbyUM5Lj3vRL0vgCKG_xfylc5wKFAk6UB8jiiKA',
...
u'https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcRj08jK8sBjX90Tu1RO4BfZkKe5A59U0g1TpMWPFZlNnA70SQ5i5DMJkvV0']

The XPath generated from an insertion point in a browser is bound to be brittle because there are many different possible XPath expressions to reach any given node, JavaScript can modify the HTML, and the browser doesn't know your intentions.
For the example you gave,
//*[#id="rg_s"]/div[13]/a/img
the 13th div is particularly prone to breakage.
Try instead to find a uniquely identifying characteristic closer to your target. A unique #id attribute would be ideal, or a #class that uniquely identifies your target or a close ancestor of your target can work well too.
For example, for Google Image Search, something like the following XPath
//div[#id='rg_s']//img[#class='rg_i']"
will select all images of class rg_i within the div containing the search results.
If you're willing to abandon the copy-and-paste approach and learn enough XPath to generalize your selections, you'll get much better results. Of course, standard disclaimers apply about changes to presentation necessitating updating of scraping techniques too. Using a direct API call would be much more robust (and proper as well).

Convert the XPath gotten from browser to usable XPath for Scrapy

This is a problem that I always have getting a specific XPath with my browser.
Assume that I want to extract all the images from some websites like Google Image Search or Pinterest. When I use Inspect element then use copy XPath to get the XPath for an image, it gives me some thing like following :
//*[#id="rg_s"]/div[13]/a/img
I got this from an image from Google Search. When I want to use it in my spider, I used Selector and HtmlXPathSelector with the following XPaths, but they all don't work!
//*[#id="rg_s"]/div/a/img
//div[#id="rg_s"]/div[13]/a/img
//[#class="rg_di rg_el"]/a/img #i change this based on the raw html of page
#hxs.select(xpath).extract()
#Selector(response).xpath('xpath')
.
.
I've read many questions, but I couldn't find a general answer to how I can use XPaths obtained from a web browser in Scrapy.

Usually it is not safe and reliable to blindly follow browser's suggestion about how to locate an element.
First of all, XPath expression that developer tools generate are usually absolute - starting from the the parent of all parents - html tag, which makes it being more dependant on the page structure (well, firebug can also make expressions based on id attributes).
Also, the HTML code you see in the browser can be pretty much different from what Scrapy receives due to asynchronous nature of the website page load and javascript being dynamically executed in the browser. Scrapy is not a browser and "sees" only the initial HTML code of a page, before the "dynamic" part.
Instead, inspect what Scrapy really has in the response: open up the Scrapy Shell, inspect the response and debug your XPath expressions and CSS selectors:
$ scrapy shell https://google.com
>>> response.xpath('//div[#id="myid"]')
...
Here is what I've got for the google image search:
$ scrapy shell "https://www.google.com/search?q=test&tbm=isch&qscrl=1"
In [1]: response.xpath('//*[#id="ires"]//img/#src').extract()
Out[1]:
[u'https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcRO9ZkSuDqt0-CRhLrWhHAyeyt41Z5I8WhOhTkGCvjiHmRiTSvDBfHKYjx_',
u'https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcQpwyzbW_qsRenDw3d4wwpwwm8n99ukMtLCVaPiTJxyviyQVBQeRCglVaY',
u'https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcSrxtoY3-3QHwhjc5Ofx8090uDYI8VOUbi3gUrd9USxZ-Vb1D5pAbOzJLMS',
u'https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcTQO1A3dDJ07tIaFMHlXNOsOnpiY_srvHKJE1xOpsMZscjL3aKGxaGLOgru',
u'https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcQ71ukeTGCPLuClWd6MetTtQ0-0mwzo3rn1ug0MUnbpXmKnwNuuBnSWXHU',
u'https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcRZmWrYR9A4W97jpjhtIbyUM5Lj3vRL0vgCKG_xfylc5wKFAk6UB8jiiKA',
...
u'https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcRj08jK8sBjX90Tu1RO4BfZkKe5A59U0g1TpMWPFZlNnA70SQ5i5DMJkvV0']

The XPath generated from an insertion point in a browser is bound to be brittle because there are many different possible XPath expressions to reach any given node, JavaScript can modify the HTML, and the browser doesn't know your intentions.
For the example you gave,
//*[#id="rg_s"]/div[13]/a/img
the 13th div is particularly prone to breakage.
Try instead to find a uniquely identifying characteristic closer to your target. A unique #id attribute would be ideal, or a #class that uniquely identifies your target or a close ancestor of your target can work well too.
For example, for Google Image Search, something like the following XPath
//div[#id='rg_s']//img[#class='rg_i']"
will select all images of class rg_i within the div containing the search results.
If you're willing to abandon the copy-and-paste approach and learn enough XPath to generalize your selections, you'll get much better results. Of course, standard disclaimers apply about changes to presentation necessitating updating of scraping techniques too. Using a direct API call would be much more robust (and proper as well).