Scrapy keyerror and next page url not working - scrapy

Question

I am trying to scrape using this page as start url: https://www.imdb.com/lists/tt0237478?ref_=tt_rls_sm
This page has 3 lists and one of the lists has 100+ items.
My code scrapes only 100 items and not fetching data from next page. Please check what is wrong with the code.
import scrapy
from urllib.parse import urljoin
class lisTopSpider(scrapy.Spider):
name= 'ImdbListsSpider'
allowed_domains = ['imdb.com']
start_urls = [
'https://www.imdb.com/lists/tt0237478'
]
def parse(self, response):
listsLinks = response.xpath('//div[2]/strong')
for link in listsLinks:
list_url = response.urljoin(link.xpath('.//a/#href').get())
yield scrapy.Request(list_url, callback=self.parse_list, meta={'list_url': list_url})
next_page_url = response.xpath('//a[#class="flat-button next-page "]/#href').get()
if next_page_url is not None:
next_page_url = response.urljoin(next_page_url)
yield scrapy.Request(next_page_url, callback=self.parse)
def parse_list(self, response):
list_url = response.meta['list_url']
titles = response.xpath('//h3/a/#href').getall()
next_page_url = response.xpath('//a[#class="flat-button lister-page-next next-page"]/#href').get()
if next_page_url is not None:
next_page_url = urljoin('https://www.imdb.com',next_page_url)
print('here is next page url')
print(next_page_url)
yield scrapy.Request(next_page_url, callback=self.parse_list)
yield{
'listurl': list_url,
'titles': titles,
}
Here is the error
2020-05-06 21:09:29 [scrapy.core.scraper] ERROR: Spider error processing <GET https://www.imdb.com/list/ls055923961/?page=2> (referer: https://www.imdb.com/list/ls055923961/)
Traceback (most recent call last):
File "c:\python projects\scrapy\imdb_project\virenv\lib\site-packages\scrapy\utils\defer.py", line 117, in iter_errback
yield next(it)
File "c:\python projects\scrapy\imdb_project\virenv\lib\site-packages\scrapy\utils\python.py", line 345, in __next__
return next(self.data)
File "c:\python projects\scrapy\imdb_project\virenv\lib\site-packages\scrapy\utils\python.py", line 345, in __next__
return next(self.data)
File "c:\python projects\scrapy\imdb_project\virenv\lib\site-packages\scrapy\core\spidermw.py", line 64, in _evaluate_iterable
for r in iterable:
File "c:\python projects\scrapy\imdb_project\virenv\lib\site-packages\scrapy\spidermiddlewares\offsite.py", line 29, in process_spider_output
for x in result:
File "c:\python projects\scrapy\imdb_project\virenv\lib\site-packages\scrapy\core\spidermw.py", line 64, in _evaluate_iterable
for r in iterable:
File "c:\python projects\scrapy\imdb_project\virenv\lib\site-packages\scrapy\spidermiddlewares\referer.py", line 338, in <genexpr>
return (_set_referer(r) for r in result or ())
File "c:\python projects\scrapy\imdb_project\virenv\lib\site-packages\scrapy\core\spidermw.py", line 64, in _evaluate_iterable
for r in iterable:
File "c:\python projects\scrapy\imdb_project\virenv\lib\site-packages\scrapy\spidermiddlewares\urllength.py", line 37,
in <genexpr>
return (r for r in result or () if _filter(r))
File "c:\python projects\scrapy\imdb_project\virenv\lib\site-packages\scrapy\core\spidermw.py", line 64, in _evaluate_iterable
for r in iterable:
File "c:\python projects\scrapy\imdb_project\virenv\lib\site-packages\scrapy\spidermiddlewares\depth.py", line 58, in <genexpr>
return (r for r in result or () if _filter(r))
File "c:\python projects\scrapy\imdb_project\virenv\lib\site-packages\scrapy\core\spidermw.py", line 64, in _evaluate_iterable
for r in iterable:
File "C:\Python Projects\Scrapy\imdb_project\imdb_project\spiders\TopLists.py", line 29, in parse_list
list_url = response.meta['list_url']
KeyError: 'list_url'

Answer 1

You are using Request.meta to provide the list_url to your parse_list-method in your parse-method but you forgot to use it in your Request-call inside of parse_list for the next pages.
Simply add meta={'list_url': list_url} to your Request inside parse_list and it should work fine.
So the handling of next pages in parse_list should look like this:
if next_page_url is not None:
next_page_url = urljoin('https://www.imdb.com', next_page_url)
yield scrapy.Request(next_page_url, callback=self.parse_list, meta={'list_url': list_url})
Btw: After Scrapy 1.7 the preferred way of handling user information is now Request.cb_kwargs (see "Caution"-part in the official docu here)