Error in extracting links from website using scrapy - scrapy

Question

When I execute the following code I am able to extract only one link instead of all the links in that specific page of website.
from scrapy import Spider
from scrapy.http import Request
class BooksSpider(Spider):
name = 'books'
allowed_domains = ['books.toscrape.com/']
start_urls= ["http://books.toscrape.com"]
def parse(self, response):
books = response.xpath("//h3/a/#href").extract()
for book in books:
absolute_url = response.urljoin(book)
yield Request(absolute_url), callback=self.parse_page)
def parse_page(self, response):
pass
This is the output which extracts only the 1st link of the website "books.toscrape.com". Can anyone help me to understand what is mistake here or is this due to some system error. This is too much frustrating now as all loops and everything else is fine. There is some issue with YIELD I guess and how can I handle this error.:
2020-05-26 12:09:23 [scrapy.utils.log] INFO: Scrapy 2.1.0 started (bot: scrap_book)
2020-05-26 12:09:23 [scrapy.utils.log] INFO: Versions: lxml 4.5.1.0, libxml2 2.9.5, cssselect 1.1.0, parsel 1.6.0, w3lib 1.22.0, Twisted 20.3.0, Python 3.8.2 (tags/v3.8.2:7b3ab59, Feb 25 2020, 22:45:29) [MSC v.1916 32 bit (Intel)], pyOpenSSL 19.1.0 (OpenSSL 1.1.1g 21 Apr 2020), cryptography 2.9.2, Platform Windows-10-10.0.18362-SP0
2020-05-26 12:09:23 [scrapy.utils.log] DEBUG: Using reactor: twisted.internet.selectreactor.SelectReactor
2020-05-26 12:09:23 [scrapy.crawler] INFO: Overridden settings:
{'BOT_NAME': 'scrap_book',
'NEWSPIDER_MODULE': 'scrap_book.spiders',
'ROBOTSTXT_OBEY': True,
'SPIDER_MODULES': ['scrap_book.spiders']}
2020-05-26 12:09:23 [scrapy.extensions.telnet] INFO: Telnet Password: 7b1edefe67af4658
2020-05-26 12:09:23 [scrapy.middleware] INFO: Enabled extensions:
['scrapy.extensions.corestats.CoreStats',
'scrapy.extensions.telnet.TelnetConsole',
'scrapy.extensions.logstats.LogStats']
2020-05-26 12:09:25 [scrapy.middleware] INFO: Enabled downloader middlewares:
['scrapy.downloadermiddlewares.robotstxt.RobotsTxtMiddleware',
'scrapy.downloadermiddlewares.httpauth.HttpAuthMiddleware',
'scrapy.downloadermiddlewares.downloadtimeout.DownloadTimeoutMiddleware',
'scrapy.downloadermiddlewares.defaultheaders.DefaultHeadersMiddleware',
'scrapy.downloadermiddlewares.useragent.UserAgentMiddleware',
'scrapy.downloadermiddlewares.retry.RetryMiddleware',
'scrapy.downloadermiddlewares.redirect.MetaRefreshMiddleware',
'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware',
'scrapy.downloadermiddlewares.redirect.RedirectMiddleware',
'scrapy.downloadermiddlewares.cookies.CookiesMiddleware',
'scrapy.downloadermiddlewares.httpproxy.HttpProxyMiddleware',
'scrapy.downloadermiddlewares.stats.DownloaderStats']
2020-05-26 12:09:25 [scrapy.middleware] INFO: Enabled spider middlewares:
['scrapy.spidermiddlewares.httperror.HttpErrorMiddleware',
'scrapy.spidermiddlewares.offsite.OffsiteMiddleware',
'scrapy.spidermiddlewares.referer.RefererMiddleware',
'scrapy.spidermiddlewares.urllength.UrlLengthMiddleware',
'scrapy.spidermiddlewares.depth.DepthMiddleware']
2020-05-26 12:09:26 [scrapy.middleware] INFO: Enabled item pipelines:
[]
2020-05-26 12:09:26 [scrapy.core.engine] INFO: Spider opened
2020-05-26 12:09:26 [scrapy.extensions.logstats] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)
2020-05-26 12:09:26 [scrapy.extensions.telnet] INFO: Telnet console listening on 127.0.0.1:6024
2020-05-26 12:09:26 [scrapy.core.engine] DEBUG: Crawled (404) <GET http://books.toscrape.com/robots.txt> (referer: None)
2020-05-26 12:09:26 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://books.toscrape.com> (referer: None)
2020-05-26 12:09:27 [scrapy.spidermiddlewares.offsite] DEBUG: Filtered offsite request to 'books.toscrape.com': <GET http://books.toscrape.com/catalogue/a-light-in-the-attic_1000/ind 'response_received_count': 2,
'robotstxt/request_count': 1,
'robotstxt/response_count': 1,
'robotstxt/response_status_count/404': 1,
'scheduler/dequeued': 1,
'scheduler/dequeued/memory': 1,
'scheduler/enqueued': 1,
'scheduler/enqueued/memory': 1,
'start_time': datetime.datetime(2020, 5, 26, 6, 24, 26, 117907)}
2020-05-26 12:09:28 [scrapy.core.engine] INFO: Spider closed (finished)

Answer 1

As Scrapy says links are filtered because of your allowed_domains:
DEBUG: Filtered offsite request to 'books.toscrape.com'
Change your code to allowed_domains = ['books.toscrape.com'] and it should work fine.
In addition, in the code you posted there is an error in the yield because there is one bracket too much right behind absolute_url. It should be: yield Request(absolute_url, callback=self.parse_page)