Scrapy Tutorial Example
<p>Looking to see if someone can point me in the right direction in regards to using Scrapy in python.</p>

<p>I've been trying to follow the example for several days and still can't get the output expected. Used the Scrapy tutorial, <a href="http://doc.scrapy.org/en/latest/intro/tutorial.html#defining-our-item" rel="nofollow">http://doc.scrapy.org/en/latest/intro/tutorial.html#defining-our-item</a>, and even download an exact project from the github repo but the output I get is not of that described in the tutorial. </p>

<pre><code>from scrapy.spiders import Spider
from scrapy.selector import Selector

from dirbot.items import Website


class DmozSpider(Spider):
name = "dmoz"
allowed_domains = ["dmoz.org"]
start_urls = [
    "http://www.dmoz.org/Computers/Programming/Languages/Python/Books/",
    "http://www.dmoz.org/Computers/Programming/Languages/Python/Resources/",
]

  def parse(self, response):
    """
    The lines below is a spider contract. For more info see:
    http://doc.scrapy.org/en/latest/topics/contracts.html

    @url http://www.dmoz.org/Computers/Programming/Languages/Python/Resources/
    @scrapes name
    """
    sel = Selector(response)
    sites = sel.xpath('//ul[@class="directory-url"]/li')
    items = []

    for site in sites:
        item = Website()
        item['name'] = site.xpath('a/text()').extract()
        item['url'] = site.xpath('a/@href').extract()
        item['description'] = site.xpath('text()').re('-\s[^\n]*\\r')
        items.append(item)

    return items
</code></pre>

<p>After I downloaded the project from github, I run "scrapy crawl dmoz" at the top level directory. I get the following output:</p>

<pre><code>2016-08-31 00:08:19 [scrapy] INFO: Scrapy 1.1.1 started (bot: scrapybot)
2016-08-31 00:08:19 [scrapy] INFO: Overridden settings: {'DEFAULT_ITEM_CLASS': 'dirbot.items.Website', 'NEWSPIDER_MODULE': 'dirbot.spiders', 'SPIDER_MODULES': ['dirbot.spiders']}
2016-08-31 00:08:19 [scrapy] INFO: Enabled extensions:
['scrapy.extensions.logstats.LogStats',
 'scrapy.extensions.telnet.TelnetConsole',
 'scrapy.extensions.corestats.CoreStats']
2016-08-31 00:08:19 [scrapy] INFO: Enabled downloader middlewares:
['scrapy.downloadermiddlewares.httpauth.HttpAuthMiddleware',
 'scrapy.downloadermiddlewares.downloadtimeout.DownloadTimeoutMiddleware',
 'scrapy.downloadermiddlewares.useragent.UserAgentMiddleware',
 'scrapy.downloadermiddlewares.retry.RetryMiddleware',
 'scrapy.downloadermiddlewares.defaultheaders.DefaultHeadersMiddleware',
 'scrapy.downloadermiddlewares.redirect.MetaRefreshMiddleware',
 'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware',
 'scrapy.downloadermiddlewares.redirect.RedirectMiddleware',
 'scrapy.downloadermiddlewares.cookies.CookiesMiddleware',
 'scrapy.downloadermiddlewares.chunked.ChunkedTransferMiddleware',
 'scrapy.downloadermiddlewares.stats.DownloaderStats']
2016-08-31 00:08:19 [scrapy] INFO: Enabled spider middlewares:
['scrapy.spidermiddlewares.httperror.HttpErrorMiddleware',
 'scrapy.spidermiddlewares.offsite.OffsiteMiddleware',
 'scrapy.spidermiddlewares.referer.RefererMiddleware',
 'scrapy.spidermiddlewares.urllength.UrlLengthMiddleware',
 'scrapy.spidermiddlewares.depth.DepthMiddleware']
2016-08-31 00:08:19 [scrapy] INFO: Enabled item pipelines:
['dirbot.pipelines.FilterWordsPipeline']
2016-08-31 00:08:19 [scrapy] INFO: Spider opened
2016-08-31 00:08:19 [scrapy] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)
2016-08-31 00:08:19 [scrapy] DEBUG: Telnet console listening on 128.1.2.1:2700
2016-08-31 00:08:20 [scrapy] DEBUG: Crawled (200) &lt;GET http://www.dmoz.org/Computers/Programming/Languages/Python/Books/&gt; (referer: None)
2016-08-31 00:08:20 [scrapy] DEBUG: Crawled (200) &lt;GET http://www.dmoz.org/Computers/Programming/Languages/Python/Resources/&gt; (referer: None)
2016-08-31 00:08:20 [scrapy] INFO: Closing spider (finished)
2016-08-31 00:08:20 [scrapy] INFO: Dumping Scrapy stats:
{'downloader/request_bytes': 514,
 'downloader/request_count': 2,
 'downloader/request_method_count/GET': 2,
 'downloader/response_bytes': 16179,
 'downloader/response_count': 2,
 'downloader/response_status_count/200': 2,
 'finish_reason': 'finished',
 'finish_time': datetime.datetime(2016, 8, 31, 7, 8, 20, 314625),
 'log_count/DEBUG': 3,
 'log_count/INFO': 7,
 'response_received_count': 2,
 'scheduler/dequeued': 2,
 'scheduler/dequeued/memory': 2,
 'scheduler/enqueued': 2,
 'scheduler/enqueued/memory': 2,
 'start_time': datetime.datetime(2016, 8, 31, 7, 8, 19, 882944)}
2016-08-31 00:08:20 [scrapy] INFO: Spider closed (finished)
</code></pre>

<p>Was expecting this per the tutorial:</p>

<pre><code>[scrapy] DEBUG: Scraped from &lt;200 http://www.dmoz.org/Computers/Programming/Languages/Python/Books/&gt;
 {'desc': [u' - By David Mertz; Addison Wesley. Book in progress, full text, ASCII format. Asks for feedback. [author website, Gnosis Software, Inc.\n],
  'link': [u'http://gnosis.cx/TPiP/'],
  'title': [u'Text Processing in Python']}
[scrapy] DEBUG: Scraped from &lt;200 http://www.dmoz.org/Computers/Programming/Languages/Python/Books/&gt;
 {'desc': [u' - By Sean McGrath; Prentice Hall PTR, 2000, ISBN 0130211192, has CD-ROM. Methods to build XML applications fast, Python tutorial, DOM and SAX, new Pyxie open source XML processing library. [Prentice Hall PTR]\n'],
  'link': [u'http://www.informit.com/store/product.aspx?isbn=0130211192'],
  'title': [u'XML Processing with Python']}
</code></pre>

<p>Seems like this spider is outdated in the tutorial. The website has changed a bit so all of the xpaths now capture nothing. This is easily fixable:</p>

<pre><code>def parse(self, response):
    sites = response.xpath('//div[@class="title-and-desc"]/a')
    for site in sites:
        item = dict()
        item['name'] = site.xpath("text()").extract_first() 
        item['url'] = site.xpath("@href").extract_first() 
        item['description'] = site.xpath("following-sibling::div/text()").extract_first('').strip()
        yield item
</code></pre>

<p>For future reference you can always test whether a specific xpath works with <code>scrapy shell</code> command.<br>
e.g. what I did to test this:</p>

<pre><code>$ scrapy shell "http://www.dmoz.org/Computers/Programming/Languages/Python/Books/"
# test sites xpath
response.xpath('//ul[@class="directory-url"]/li') 
[]
# ok it doesn't work, check out page in web browser
view(response)
# find correct xpath and test that:
response.xpath('//div[@class="title-and-desc"]/a')
# 21 result nodes printed
# it works!
</code></pre>

python web-scraping scrapy web-crawler