我正试图刮掉国会图书馆/托马斯网站。此Python脚本旨在从其站点访问40个帐单的样本（URL中的＃1-40标识符）。我想解析每个立法的正文，搜索正文/内容，提取潜在的多个版本的链接＆amp;跟随。
在版本页面上，我想解析每一条立法的正文，搜索正文/内容＆amp;提取潜在部分的链接＆amp;跟随。
一旦进入部分页面，我想解析账单每一部分的正文。
我认为我的代码的Rules / LinkExtractor段存在一些问题。 python代码正在执行，抓取起始URL，但不解析或任何后续任务。
三个问题：
我的问题是，为什么Scrapy不会抓取或解析？
from scrapy.item import Item, Field
from scrapy.contrib.spiders import CrawlSpider, Rule
from scrapy.contrib.linkextractors.sgml import SgmlLinkExtractor
from scrapy.selector import HtmlXPathSelector
class BillItem(Item):
title = Field()
body = Field()
class VersionItem(Item):
title = Field()
body = Field()
class SectionItem(Item):
body = Field()
class Lrn2CrawlSpider(CrawlSpider):
name = "lrn2crawl"
allowed_domains = ["thomas.loc.gov"]
start_urls = ["http://thomas.loc.gov/cgi-bin/query/z?c107:H.R.%s:" % bill for bill in xrange(000001,00040,00001) ### Sample of 40 bills; Total range of bills is 1-5767
]
rules = (
# Extract links matching /query/ fragment (restricting tho those inside the content body of the url)
# and follow links from them (since no callback means follow=True by default).
# Desired result: scrape all bill text & in the event that there are multiple versions, follow them & parse.
Rule(SgmlLinkExtractor(allow=(r'/query/'), restrict_xpaths=('//div[@id="content"]')), callback='parse_bills', follow=True),
# Extract links in the body of a bill-version & follow them.
#Desired result: scrape all version text & in the event that there are multiple sections, follow them & parse.
Rule(SgmlLinkExtractor(restrict_xpaths=('//div/a[2]')), callback='parse_versions', follow=True)
)
def parse_bills(self, response):
hxs = HtmlXPathSelector(response)
bills = hxs.select('//div[@id="content"]')
scraped_bills = []
for bill in bills:
scraped_bill = BillItem() ### Bill object defined previously
scraped_bill['title'] = bill.select('p/text()').extract()
scraped_bill['body'] = response.body
scraped_bills.append(scraped_bill)
return scraped_bills
def parse_versions(self, response):
hxs = HtmlXPathSelector(response)
versions = hxs.select('//div[@id="content"]')
scraped_versions = []
for version in versions:
scraped_version = VersionItem() ### Version object defined previously
scraped_version['title'] = version.select('center/b/text()').extract()
scraped_version['body'] = response.body
scraped_versions.append(scraped_version)
return scraped_versions
def parse_sections(self, response):
hxs = HtmlXPathSelector(response)
sections = hxs.select('//div[@id="content"]')
scraped_sections = []
for section in sections:
scraped_section = SectionItem() ## Segment object defined previously
scraped_section['body'] = response.body
scraped_sections.append(scraped_section)
return scraped_sections
spider = Lrn2CrawlSpider()
答案 0 :(得分：1)
仅为了记录，您的脚本存在的问题是变量rules不在Lrn2CrawlSpider的范围内，因为它不共享相同的缩进，因此当alecxe时修复了缩进，变量rules现在变成了类的属性。稍后，继承的方法__init__()读取属性并编译规则并强制执行它们。
def __init__(self, *a, **kw):
super(CrawlSpider, self).__init__(*a, **kw)
self._compile_rules()
删除最后一行与此无关。
答案 1 :(得分：0)
我刚刚修改了缩进，在脚本末尾删除了spider = Lrn2CrawlSpider()行，通过scrapy runspider lrn2crawl.py运行了蜘蛛并且它会刮擦，跟踪链接，返回项目 - 您的规则有效。
这就是我正在运行的内容：
from scrapy.item import Item, Field
from scrapy.contrib.spiders import CrawlSpider, Rule
from scrapy.contrib.linkextractors.sgml import SgmlLinkExtractor
from scrapy.selector import HtmlXPathSelector
class BillItem(Item):
title = Field()
body = Field()
class VersionItem(Item):
title = Field()
body = Field()
class SectionItem(Item):
body = Field()
class Lrn2CrawlSpider(CrawlSpider):
name = "lrn2crawl"
allowed_domains = ["thomas.loc.gov"]
start_urls = ["http://thomas.loc.gov/cgi-bin/query/z?c107:H.R.%s:" % bill for bill in xrange(000001,00040,00001) ### Sample of 40 bills; Total range of bills is 1-5767
]
rules = (
# Extract links matching /query/ fragment (restricting tho those inside the content body of the url)
# and follow links from them (since no callback means follow=True by default).
# Desired result: scrape all bill text & in the event that there are multiple versions, follow them & parse.
Rule(SgmlLinkExtractor(allow=(r'/query/'), restrict_xpaths=('//div[@id="content"]')), callback='parse_bills', follow=True),
# Extract links in the body of a bill-version & follow them.
#Desired result: scrape all version text & in the event that there are multiple sections, follow them & parse.
Rule(SgmlLinkExtractor(restrict_xpaths=('//div/a[2]')), callback='parse_versions', follow=True)
)
def parse_bills(self, response):
hxs = HtmlXPathSelector(response)
bills = hxs.select('//div[@id="content"]')
scraped_bills = []
for bill in bills:
scraped_bill = BillItem() ### Bill object defined previously
scraped_bill['title'] = bill.select('p/text()').extract()
scraped_bill['body'] = response.body
scraped_bills.append(scraped_bill)
return scraped_bills
def parse_versions(self, response):
hxs = HtmlXPathSelector(response)
versions = hxs.select('//div[@id="content"]')
scraped_versions = []
for version in versions:
scraped_version = VersionItem() ### Version object defined previously
scraped_version['title'] = version.select('center/b/text()').extract()
scraped_version['body'] = response.body
scraped_versions.append(scraped_version)
return scraped_versions
def parse_sections(self, response):
hxs = HtmlXPathSelector(response)
sections = hxs.select('//div[@id="content"]')
scraped_sections = []
for section in sections:
scraped_section = SectionItem() ## Segment object defined previously
scraped_section['body'] = response.body
scraped_sections.append(scraped_section)
return scraped_sections
希望有所帮助。