how to select and extract texts between two elements?

Question

I am trying to scrape this website using scrapy. The page structure looks like this:

  <         


        

                      

              相关标签:
       
      

Answer 1

You can try to use below XPath expressions to fetch

• all text nodes for "Follows" block:

  //div[./preceding-sibling::h4[1]="Follows"]//text()
  

• all text nodes for "Followed by" block:

  //div[./preceding-sibling::h4[1]="Followed by"]//text()
  

• all text nodes for "Spin off" block:

  //div[./preceding-sibling::h4[1]="Spin-off"]//text()
  

Answer 2

An extraction pattern I like to use for these cases is:

• loop over the "boundaries" (here, h4 elements)
• while enumerating them starting from 1
• using XPath's following-sibling axis, like in @Andersson's answer, to get elements before the next boundary,
• and filtering them by counting the number of preceding "boundary" elements, since we know from our enumeration where we are

This would be the loop:

$ scrapy shell 'http://www.imdb.com/title/tt0092455/trivia?tab=mc&ref_=tt_trv_cnn'
(...)
>>> for cnt, h4 in enumerate(response.css('div.list > h4.li_group'), start=1):
...     print(cnt, h4.xpath('normalize-space()').get())
... 
1 Follows 
2 Followed by 
3 Edited into 
4 Spun-off from 
5 Spin-off 
6 Referenced in 
7 Featured in 
8 Spoofed in 

And this is one example of using the enumeration to get elements between boundaries (note that this use XPath variables with $cnt in the expression and passing cnt=cnt in .xpath()):

>>> for cnt, h4 in enumerate(response.css('div.list > h4.li_group'), start=1):
...     print(cnt, h4.xpath('normalize-space()').get())
...     print(h4.xpath('following-sibling::div[count(preceding-sibling::h4)=$cnt]',
                       cnt=cnt).xpath(
                          'string(.//a)').getall())
... 
1 Follows 
['Star Trek', 'Star Trek: The Animated Series', 'Star Trek: The Motion Picture', 'Star Trek II: The Wrath of Khan', 'Star Trek III: The Search for Spock', 'Star Trek IV: The Voyage Home']
2 Followed by 
['Star Trek V: The Final Frontier', 'Star Trek VI: The Undiscovered Country', 'Star Trek: Deep Space Nine', 'Star Trek: Generations', 'Star Trek: Voyager', 'First Contact', 'Star Trek: Insurrection', 'Star Trek: Enterprise', 'Star Trek: Nemesis', 'Star Trek', 'Star Trek Into Darkness', 'Star Trek Beyond', 'Star Trek: Discovery', 'Untitled Star Trek Sequel']
3 Edited into 
['Reading Rainbow: The Bionic Bunny Show', 'The Unauthorized Hagiography of Vincent Price']
4 Spun-off from 
['Star Trek']
5 Spin-off 
['Star Trek: The Next Generation - The Transinium Challenge', 'A Night with Troi', 'Star Trek: Deep Space Nine', "Star Trek: The Next Generation - Future's Past", 'Star Trek: The Next Generation - A Final Unity', 'Star Trek: The Next Generation: Interactive VCR Board Game - A Klingon Challenge', 'Star Trek: Borg', 'Star Trek: Klingon', 'Star Trek: The Experience - The Klingon Encounter']
6 Referenced in 
(...)

Here's how you could use that to populate and item (here, I'm using a simple dict just for illustration):

>>> item = {}
>>> for cnt, h4 in enumerate(response.css('div.list > h4.li_group'), start=1):
...     key = h4.xpath('normalize-space()').get().strip() # there are some non-breaking spaces
...     if key in ['Follows', 'Followed by', 'Spin-off']:
...         values = h4.xpath('following-sibling::div[count(preceding-sibling::h4)=$cnt]',
...                        cnt=cnt).xpath(
...                           'string(.//a)').getall()
...         item[key] = values
... 

>>> from pprint import pprint
>>> pprint(item)
{'Followed by': ['Star Trek V: The Final Frontier',
                 'Star Trek VI: The Undiscovered Country',
                 'Star Trek: Deep Space Nine',
                 'Star Trek: Generations',
                 'Star Trek: Voyager',
                 'First Contact',
                 'Star Trek: Insurrection',
                 'Star Trek: Enterprise',
                 'Star Trek: Nemesis',
                 'Star Trek',
                 'Star Trek Into Darkness',
                 'Star Trek Beyond',
                 'Star Trek: Discovery',
                 'Untitled Star Trek Sequel'],
 'Follows': ['Star Trek',
             'Star Trek: The Animated Series',
             'Star Trek: The Motion Picture',
             'Star Trek II: The Wrath of Khan',
             'Star Trek III: The Search for Spock',
             'Star Trek IV: The Voyage Home'],
 'Spin-off': ['Star Trek: The Next Generation - The Transinium Challenge',
              'A Night with Troi',
              'Star Trek: Deep Space Nine',
              "Star Trek: The Next Generation - Future's Past",
              'Star Trek: The Next Generation - A Final Unity',
              'Star Trek: The Next Generation: Interactive VCR Board Game - A '
              'Klingon Challenge',
              'Star Trek: Borg',
              'Star Trek: Klingon',
              'Star Trek: The Experience - The Klingon Encounter']}
>>>