Scrapy 请求返回 notImplementedError
我的scrapy代码不起作用，我不知道！我想抓取宜家网站，我首先设计了一个 CrawlSpider，它不够具体，无法检索网页的每个链接.所以我设计了一个带有yield请求方法的基本Spider.
My scrapy code doesn't work and I have no clue ! I want to scrape the Ikea website, I designed first a CrawlSpider which was not specific enough to retrieve every links of the webpage. So I designed a basic Spider with yield request method.
这是我的代码:
class IkeaSpider(scrapy.Spider) :
name = "Ikea"
allower_domains = ["http://www.ikea.com/"]
start_urls = ["http://www.ikea.com/fr/fr/catalog/productsaz/8/"]
def parse_url(self, response):
for sel in response.xpath('//div[@id="productsAzLeft"]'):
base_url = 'http://www.ikea.com/'
follow_url = sel.xpath('//span[@class="productsAzLink"]/@href').extract()
complete_url = urlparse.urljoin(base_url, follow_url)
request = Request(complete_url, callback = self.parse_page)
yield request
def parse_page(self, response):
这里是错误日志:
2016-01-04 22:06:31 [scrapy] ERROR: Spider error processing <GET http://www.ikea.com/fr/fr/catalog/productsaz/8/> (referer: None)
Traceback (most recent call last):
File "/usr/local/lib/python2.7/dist-packages/twisted/internet/defer.py", line 588, in _runCallbacks
current.result = callback(current.result, *args, **kw)
File "/usr/local/lib/python2.7/dist-packages/scrapy/spiders/__init__.py", line 76, in parse
raise NotImplementedError
NotImplementedError
你的蜘蛛需要一个 parse 方法，它是所有初始请求的默认回调.您只需将 parse_url 方法重命名为 parse 就可以了.
Your spider needs a parse method which is the default callback for all initial requests. You can just rename the parse_url method to parse and it will work fine.
class IkeaSpider(scrapy.Spider) :
name = "Ikea"
allower_domains = ["http://www.ikea.com/"]
start_urls = ["http://www.ikea.com/fr/fr/catalog/productsaz/8/"]
def parse(self, response):
for sel in response.xpath('//div[@id="productsAzLeft"]'):
base_url = 'http://www.ikea.com/'
follow_url = sel.xpath('//span[@class="productsAzLink"]/@href').extract()
complete_url = urlparse.urljoin(base_url, follow_url)
request = Request(complete_url, callback = self.parse_page)
yield request
替代方案
您还可以定义一个 start_requests 方法并使用定义的 callback 参数手动生成 scrapy.Requests，就像您在此处所做的那样.
Alternatives
You can also define a start_requests method and yield scrapy.Requests manually with a defined callback argument just like you did here.