[英]Meta tag is not working in scrapy python
我正在工作scrapy框架,下面是我的spider.py代码
class Example(BaseSpider):
name = "example"
allowed_domains = {"http://www.example.com"}
start_urls = [
"http://www.example.com/servlet/av/search&SiteName=page1"
]
def parse(self, response):
hxs = HtmlXPathSelector(response)
hrefs = hxs.select('//table[@class="knxa"]/tr/td/a/@href').extract()
# href consists of all href tags and i am copying in to forwarding_hrefs by making them as a string
forwarding_hrefs = []
for i in hrefs:
forwarding_hrefs.append(i.encode('utf-8'))
return Request('http://www.example.com/servlet/av/search&SiteName=page2',
meta={'forwarding_hrefs': response.meta['forwarding_hrefs']},
callback=self.parseJob)
def parseJob(self, response):
print response,">>>>>>>>>>>"
结果:
2012-07-18 17:29:15+0530 [example] DEBUG: Crawled (200) <GET http://www.example.com/servlet/av/search&SiteName=page1> (referer: None)
2012-07-18 17:29:15+0530 [MemorialReqionalHospital] ERROR: Spider error processing <GET http://www.example.com/servlet/av/search&SiteName=page2>
Traceback (most recent call last):
File "/usr/lib64/python2.7/site-packages/twisted/internet/base.py", line 1167, in mainLoop
self.runUntilCurrent()
File "/usr/lib64/python2.7/site-packages/twisted/internet/base.py", line 789, in runUntilCurrent
call.func(*call.args, **call.kw)
File "/usr/lib64/python2.7/site-packages/twisted/internet/defer.py", line 361, in callback
self._startRunCallbacks(result)
File "/usr/lib64/python2.7/site-packages/twisted/internet/defer.py", line 455, in _startRunCallbacks
self._runCallbacks()
--- <exception caught here> ---
File "/usr/lib64/python2.7/site-packages/twisted/internet/defer.py", line 542, in _runCallbacks
current.result = callback(current.result, *args, **kw)
File "/home/local/user/project/example/example/spiders/example_spider.py", line 36, in parse
meta={'forwarding_hrefs': response.meta['forwarding_hrefs']},
exceptions.KeyError: 'forwarding_hrefs'
我正在尝试做的是从中收集所有href标签
http://www.example.com/servlet/av/search&SiteName=page1
并放入forward_hrefs
并在下一个请求中调用此forward_hrefs
(想在下一个方法中使用此forward_urls
列表)
http://www.example.com/servlet/av/search&SiteName=page2
我还想将来自第2页的href标记添加到forward_urls中,并在这个forward_hrefs
循环并产生每个href标记的请求,这是我的想法,但它显示了上述错误,上述代码有什么错误,实际上是meta标记的意思复制项目。 谁能让我知道这是如何将forward_hrefs
列表从parse
方法复制到parseJob
方法的。
最后,我的目的是将forward_hrefs
列表从parse
方法复制到parseJob
方法。
希望我能很好地解释,如果不能,请告诉我。
提前致谢
尚未尝试任何操作,但似乎您在这里遇到错误:
return Request('http://www.example.com/servlet/av/search&SiteName=page2',
meta={'forwarding_hrefs': response.meta['forwarding_hrefs']},
callback=self.parseJob)
您正在传递response.meta ['forwarding_hrefs'],但此响应不存在
您需要输入:
return Request('http://www.example.com/servlet/av/search&SiteName=page2',
meta={'forwarding_hrefs': forwarding_hrefs},
callback=self.parseJob)
导致您具有forward_hrefs字段,通过这种方式,您将其发送到meta内部的解析作业中,然后在meta内部,您将能够访问response.meta ['forwarding_hrefs'],因为它将存在于该响应对象中。
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