问题
A genuine Scrapy and Python noob here so please be patient with any silly mistakes. I'm trying to write a spider to recursively crawl a news site and return the headline, date, and first paragraph of the Article. I managed to crawl a single page for one item but the moment I try and expand beyond that it all goes wrong.
my Spider:
import scrapy
from scrapy.contrib.spiders import CrawlSpider, Rule
from scrapy.selector import Selector
from scrapy.contrib.linkextractors.sgml import SgmlLinkExtractor
from basic.items import BasicItem
class BasicSpiderSpider(CrawlSpider):
name = "basic_spider"
allowed_domains = ["news24.com/"]
start_urls = (
'http://www.news24.com/SouthAfrica/News/56-children-hospitalised-for-food-poisoning-20150328',
)
rules = (Rule (SgmlLinkExtractor(allow=("", ))
, callback="parse_items", follow= True),
)
def parse_items(self, response):
hxs = Selector(response)
titles = hxs.xpath('//*[@id="aspnetForm"]')
items = []
item = BasicItem()
item['Headline'] = titles.xpath('//*[@id="article_special"]//h1/text()').extract()
item["Article"] = titles.xpath('//*[@id="article-body"]/p[1]/text()').extract()
item["Date"] = titles.xpath('//*[@id="spnDate"]/text()').extract()
items.append(item)
return items
I am still getting the same problem, though have noticed that there is a "[" for every time I try and run the spider, to try and figure out what the issue is I have run the following command:
c:\Scrapy Spiders\basic>scrapy parse --spider=basic_spider -c parse_items -d 2 -v http://www.news24.com/SouthAfrica/News/56-children-hospitalised-for-food-poisoning-20150328
which gives me the following output:
2015-03-30 15:28:21+0200 [scrapy] INFO: Scrapy 0.24.5 started (bot: basic)
2015-03-30 15:28:21+0200 [scrapy] INFO: Optional features available: ssl, http11
2015-03-30 15:28:21+0200 [scrapy] INFO: Overridden settings: {'NEWSPIDER_MODULE': 'basic.spiders', 'SPIDER_MODULES': ['basic.spiders'], 'DEPTH_LIMIT': 1, 'DOW
NLOAD_DELAY': 2, 'BOT_NAME': 'basic'}
2015-03-30 15:28:21+0200 [scrapy] INFO: Enabled extensions: LogStats, TelnetConsole, CloseSpider, WebService, CoreStats, SpiderState
2015-03-30 15:28:21+0200 [scrapy] INFO: Enabled downloader middlewares: HttpAuthMiddleware, DownloadTimeoutMiddleware, UserAgentMiddleware, RetryMiddleware, D
efaultHeadersMiddleware, MetaRefreshMiddleware, HttpCompressionMiddleware, RedirectMiddleware, CookiesMiddleware, ChunkedTransferMiddleware, DownloaderStats
2015-03-30 15:28:21+0200 [scrapy] INFO: Enabled spider middlewares: HttpErrorMiddleware, OffsiteMiddleware, RefererMiddleware, UrlLengthMiddleware, DepthMiddl
eware
2015-03-30 15:28:21+0200 [scrapy] INFO: Enabled item pipelines:
2015-03-30 15:28:21+0200 [basic_spider] INFO: Spider opened
2015-03-30 15:28:21+0200 [basic_spider] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)
2015-03-30 15:28:21+0200 [scrapy] DEBUG: Telnet console listening on 127.0.0.1:6023
2015-03-30 15:28:21+0200 [scrapy] DEBUG: Web service listening on 127.0.0.1:6080
2015-03-30 15:28:22+0200 [basic_spider] DEBUG: Crawled (200) <GET http://www.news24.com/SouthAfrica/News/56-children-hospitalised-for-food-poisoning-20150328>
(referer: None)
2015-03-30 15:28:22+0200 [basic_spider] INFO: Closing spider (finished)
2015-03-30 15:28:22+0200 [basic_spider] INFO: Dumping Scrapy stats:
{'downloader/request_bytes': 282,
'downloader/request_count': 1,
'downloader/request_method_count/GET': 1,
'downloader/response_bytes': 145301,
'downloader/response_count': 1,
'downloader/response_status_count/200': 1,
'finish_reason': 'finished',
'finish_time': datetime.datetime(2015, 3, 30, 13, 28, 22, 177000),
'log_count/DEBUG': 3,
'log_count/INFO': 7,
'response_received_count': 1,
'scheduler/dequeued': 1,
'scheduler/dequeued/memory': 1,
'scheduler/enqueued': 1,
'scheduler/enqueued/memory': 1,
'start_time': datetime.datetime(2015, 3, 30, 13, 28, 21, 878000)}
2015-03-30 15:28:22+0200 [basic_spider] INFO: Spider closed (finished)
>>> DEPTH LEVEL: 1 <<<
# Scraped Items ------------------------------------------------------------
[{'Article': [u'Johannesburg - Fifty-six children were taken to\nPietermaritzburg hospitals after showing signs of food poisoning while at\nschool, KwaZulu-Na
tal emergency services said on Friday.'],
'Date': [u'2015-03-28 07:30'],
'Headline': [u'56 children hospitalised for food poisoning']}]
# Requests -----------------------------------------------------------------
[]
So, I can see that the Item is being scraped, but there is no usable item data put into the json file. this is how i'm running scrapy:
scrapy crawl basic_spider -o test.json
I've been looking at the last line, (return items) as changing it to either yield or print gives me no items scraped in the parse.
回答1:
This usually means nothing was scraped, no items were extracted.
In your case, fix your allowed_domains setting:
allowed_domains = ["news24.com"]
Aside from that, just a bit cleaning up from a perfectionist:
from scrapy.contrib.spiders import CrawlSpider, Rule
from scrapy.contrib.linkextractors import LinkExtractor
class BasicSpiderSpider(CrawlSpider):
name = "basic_spider"
allowed_domains = ["news24.com"]
start_urls = [
'http://www.news24.com/SouthAfrica/News/56-children-hospitalised-for-food-poisoning-20150328',
]
rules = [
Rule(LinkExtractor(), callback="parse_items", follow=True),
]
def parse_items(self, response):
for title in response.xpath('//*[@id="aspnetForm"]'):
item = BasicItem()
item['Headline'] = title.xpath('//*[@id="article_special"]//h1/text()').extract()
item["Article"] = title.xpath('//*[@id="article-body"]/p[1]/text()').extract()
item["Date"] = title.xpath('//*[@id="spnDate"]/text()').extract()
yield item
来源：https://stackoverflow.com/questions/29348425/scrapy-outputs-into-my-json-file