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Scraping a domain for links recursively using Scrapy

Here is the code I'm using for scraping all the urls of a domain:
import scrapy
from scrapy.spiders import CrawlSpider, Rule
from scrapy.linkextractors.lxmlhtml import LxmlLinkExtractor
class UrlsSpider(scrapy.Spider):
name = 'urlsspider'
allowed_domains = ['example.com']
start_urls = ['http://example.com/']
rules = (Rule(LxmlLinkExtractor(allow=(), unique=True), callback='parse', follow=True))
def parse(self, response):
for link in LxmlLinkExtractor(allow_domains=self.allowed_domains, unique=True).extract_links(response):
print link.url
yield scrapy.Request(link.url, callback=self.parse)
As you can see that I've used unique=True but it's still printing duplicate urls in the terminal whereas I want only the unique urls and not duplicate urls.
Any help on this matter will be very helpful.

Since the code looks at the content of the URLs recursively, you will see the duplicate URLs from the parsing of other pages. You essentially have multiple instances of LxmlLinkExtractor().

CrawlSpider can't parse multipage in Scrapy

The CrawlSpider I've created is not doing it's job properly. It parses the first page and then stops without going on to the next page. Something I'm doing wrong but can't detect. Hope somebody out there gives me a hint what should I do to rectify it.
"items.py" includes:
from scrapy.item import Item, Field
class CraigslistScraperItem(Item):
Name = Field()
Link = Field()
CrawlSpider names "craigs.py" which contains :
from scrapy.contrib.spiders import CrawlSpider, Rule
from scrapy.linkextractors import LinkExtractor
from scrapy.selector import Selector
from craigslist_scraper.items import CraigslistScraperItem
class CraigsPySpider(CrawlSpider):
name = "craigs"
allowed_domains = ["craigslist.org"]
start_urls = (
'http://sfbay.craigslist.org/search/npo/',
)
rules=(Rule(LinkExtractor(allow = ('sfbay\.craigslist\.org\/search\/npo/.*',
),restrict_xpaths = ('//a[#class="button next"]')),callback = 'parse',follow = True),)
def parse(self, response):
page=response.xpath('//p[#class="result-info"]')
items=[]
for title in page:
item=CraigslistScraperItem()
item["Name"]=title.xpath('.//a[#class="result-title hdrlnk"]/text()').extract()
item["Link"]=title.xpath('.//a[#class="result-title hdrlnk"]/#href').extract()
items.append(item)
return items
And finally the command I'm using to get CSV output is:
scrapy crawl craigs -o items.csv -t csv
By the way, I tried to use "parse_item" in the first place but found no response that is why I used "parse" method instead. Thanks in advance.

Don't name your callback method parse when you use scrapy.CrawlSpider.
From Scrapy documentation:
When writing crawl spider rules, avoid using parse as callback, since
the CrawlSpider uses the parse method itself to implement its logic.
So if you override the parse method, the crawl spider will no longer
work.
Also, you don't need to append an item to list since you already using Scrapy Items and can simply yield item.
This code should work:
# -*- coding: utf-8 -*-
from scrapy.contrib.spiders import CrawlSpider, Rule
from scrapy.linkextractors import LinkExtractor
from craigslist_scraper.items import CraigslistScraperItem
class CraigsPySpider(CrawlSpider):
name = "craigs"
allowed_domains = ["craigslist.org"]
start_urls = (
'http://sfbay.craigslist.org/search/npo/',
)
rules = (
Rule(LinkExtractor(allow=('\/search\/npo\?s=.*',)), callback='parse_item', follow=True),
)
def parse_item(self, response):
page = response.xpath('//p[#class="result-info"]')
for title in page:
item = CraigslistScraperItem()
item["Name"] = title.xpath('.//a[#class="result-title hdrlnk"]/text()').extract_first()
item["Link"] = title.xpath('.//a[#class="result-title hdrlnk"]/#href').extract_first()
yield item
Finally for output in csv format run: scrapy crawl craigs -o items.csv

scrapy crawlspider output

I'm having an issue running through the CrawlSpider example in the Scrapy documentation. It seems to be crawling just fine but I'm having trouble getting it to output to a CSV file (or anything really).
So, my question is can I use this:
scrapy crawl dmoz -o items.csv
or do I have to create an Item Pipeline?
UPDATED, now with code!:
import scrapy
from scrapy.contrib.spiders import CrawlSpider, Rule
from scrapy.contrib.linkextractors import LinkExtractor
from targets.item import TargetsItem
class MySpider(CrawlSpider):
name = 'abc'
allowed_domains = ['ididntuseexample.com']
start_urls = ['http://www.ididntuseexample.com']
rules = (
# Extract links matching 'category.php' (but not matching 'subsection.php')
# and follow links from them (since no callback means follow=True by default).
Rule(LinkExtractor(allow=('ididntuseexample.com', ))),
)
def parse_item(self, response):
self.log('Hi, this is an item page! %s' % response.url)
item = TargetsItem()
item['title'] = response.xpath('//h2/a/text()').extract() #this pulled down data in scrapy shell
item['link'] = response.xpath('//h2/a/#href').extract() #this pulled down data in scrapy shell
return item

Rules are the mechanism CrawlSpider uses for following links. Those links are defined with a LinkExtractor. This element basically indicates which links to extract from the crawled page (like the ones defined in the start_urls list) to be followed. Then you can pass a callback that will be called on each extracted link, or more precise, on the pages downloaded following those links.
Your rule must call the parse_item. So, replace:
Rule(LinkExtractor(allow=('ididntuseexample.com', ))),
with:
Rule(LinkExtractor(allow=('ididntuseexample.com',)), callback='parse_item),
This rule defines that you want to call parse_item on every link whose href is ididntuseexample.com. I suspect that what you want as link extractor is not the domain, but the links you want to follow/scrape.
Here you have a basic example that crawls Hacker News to retrieve the title and the first lines of the first comment for all the news in the main page.
import scrapy
from scrapy.contrib.spiders import CrawlSpider, Rule
from scrapy.contrib.linkextractors import LinkExtractor
class HackerNewsItem(scrapy.Item):
title = scrapy.Field()
comment = scrapy.Field()
class HackerNewsSpider(CrawlSpider):
name = 'hackernews'
allowed_domains = ['news.ycombinator.com']
start_urls = [
'https://news.ycombinator.com/'
]
rules = (
# Follow any item link and call parse_item.
Rule(LinkExtractor(allow=('item.*', )), callback='parse_item'),
)
def parse_item(self, response):
item = HackerNewsItem()
# Get the title
item['title'] = response.xpath('//*[contains(#class, "title")]/a/text()').extract()
# Get the first words of the first comment
item['comment'] = response.xpath('(//*[contains(#class, "comment")])[1]/font/text()').extract()
return item

I can't get the data using Rules on scrapy

i'm doing a spider with scrapy that works if i don't implement any rules, but now i'm trying to implement a Rule to get paginator and scrape all the rest of pages. But i don't know why i can't achieve it.
Spider code:
allowed_domains = ['guia.bcn.cat']
start_urls = ['http://guia.bcn.cat/index.php?pg=search&q=*:*']
rules = (
Rule(SgmlLinkExtractor(allow=("index.php?pg=search&from=10&q=*:*&nr=10"),
restrict_xpaths=("//div[#class='paginador']",))
, callback="parse_item", follow=True),)
def parse_item(self, response)
...
Also, i tried to set "index.php" in allow parameter of the rule, but neither works.
I read in scrapy groups that i have not put "a/" or "a/#href" because SgmlLinkExtractor search automatically the link.
Console output seems to work well but don't get anything.
Any idea?
Thanks in advance
EDIT:
With this code works
from scrapy.selector import Selector
from scrapy.contrib.linkextractors.sgml import SgmlLinkExtractor
from scrapy.contrib.spiders import CrawlSpider, Rule
from bcncat.items import BcncatItem
import re
class BcnSpider(CrawlSpider):
name = 'bcn'
allowed_domains = ['guia.bcn.cat']
start_urls = ['http://guia.bcn.cat/index.php?pg=search&q=*:*']
rules = (
Rule(
SgmlLinkExtractor(
allow=(re.escape("index.php")),
restrict_xpaths=("//div[#class='paginador']")),
callback="parse_item",
follow=True),
)
def parse_item(self, response):
self.log("parse_item")
sel = Selector(response)
i = BcncatItem()
#i['domain_id'] = sel.xpath('//input[#id="sid"]/#value').extract()
#i['name'] = sel.xpath('//div[#id="name"]').extract()
#i['description'] = sel.xpath('//div[#id="description"]').extract()
return i

The allow parameter for SgmlLinkExtractor is a (list of) regular expression(s). So "?", "*" and "." are treated as special characters.
You can use allow=(re.escape("index.php?pg=search&from=10&q=*:*&nr=10")) (with import re somewhere at the beginning of your script)
EDIT: in fact, the above rule doesn't work. But as you already have the restricted region where you want to extract links, you can use allow=('index.php')

crawling multiple webpages from a website

from scrapy.spider import BaseSpider
from scrapy.selector import HtmlXPathSelector
class DmozSpider(BaseSpider):
name = "dmoz"
allowed_domains = ["dmoz.org"]
start_urls = [
"www.dmoz.org/Computers/Programming/Languages/Python/Books/",
"www.dmoz.org/Computers/Programming/Languages/Python/Resources/"
]
def parse(self, response):
hxs = HtmlXPathSelector(response)
sites = hxs.select('//ul/li')
for site in sites:
title = site.select('a/text()').extract()
link = site.select('a/#href').extract()
desc = site.select('text()').extract()
print title, link, desc
This is my code. I want plenty of URLs to scrape using loop. So how am I suposed to these? I did put multiple urls in there but I didn't get output from all of them. Some URLs stop responding. So how can I get the data for sure using this code?

You code looks ok but are you sure that start_urls shouldn't start with http://
start_urls = [
"http://www.dmoz.org/Computers/Programming/Languages/Python/Books/",
"http://www.dmoz.org/Computers/Programming/Languages/Python/Resources/"
]
UPD
start_urls is a list of urls scrapy starts with. Usually it has one or two links. Rarely more.
This pages must have identical HTML structure because Scrapy spider process them the same way.
See if i put 4-5 url's in start_urls it gives output ok for first 2-3
url's.
I don't believe this because scrapy doesn't care how many links is start_urls list.
But it stops responding and also tell me how i can implement GUI for this.?
Scrapy has debug shell to test you code.

You just posted the code from the tutorial. What you should do is to actually read the whole documentation, especially the basic concept part. What you basically want is the crawl spider where you can define rules that the spider will follow and process with your given code.
To quote the docs with the example:
from scrapy.contrib.spiders import CrawlSpider, Rule
from scrapy.contrib.linkextractors.sgml import SgmlLinkExtractor
from scrapy.selector import HtmlXPathSelector
from scrapy.item import Item
class MySpider(CrawlSpider):
name = 'example.com'
allowed_domains = ['example.com']
start_urls = ['http://www.example.com']
rules = (
# Extract links matching 'category.php' (but not matching 'subsection.php')
# and follow links from them (since no callback means follow=True by default).
Rule(SgmlLinkExtractor(allow=('category\.php', ), deny=('subsection\.php', ))),
# Extract links matching 'item.php' and parse them with the spider's method parse_item
Rule(SgmlLinkExtractor(allow=('item\.php', )), callback='parse_item'),
)
def parse_item(self, response):
self.log('Hi, this is an item page! %s' % response.url)
hxs = HtmlXPathSelector(response)
item = Item()
item['id'] = hxs.select('//td[#id="item_id"]/text()').re(r'ID: (\d+)')
item['name'] = hxs.select('//td[#id="item_name"]/text()').extract()
item['description'] = hxs.select('//td[#id="item_description"]/text()').extract()
return item