3

我写了一个蜘蛛，第一次效果很好。我第二次尝试运行它时，它并没有超出start_urls. 我尝试fetch输入 url并从返回的响应中scrapy shell创建一个对象。HtmlXPathSelector那是我得到错误的时候

所以步骤是：`

[scrapy shell] fetch('http://example.com') #its something other than example.
[scrapy shell] from scrapy.selector import HtmlXPathSelector
[scrapy shell] hxs = HtmlXPathSelector(response)

---------------------------------------------------------------------------

追溯：

AttributeError                            Traceback (most recent call last)
<ipython-input-3-a486208adf1e> in <module>()
----> 1 HtmlXPathSelector(response)

/home/codefreak/project-r42catalog/env-r42catalog/lib/python2.7/site-packages/scrapy/selector/lxmlsel.pyc in __init__(self, response, text, namespaces, _root, _expr)
     29                 body=unicode_to_str(text, 'utf-8'), encoding='utf-8')
     30         if response is not None:
---> 31             _root = LxmlDocument(response, self._parser)
     32 
     33         self.namespaces = namespaces

/home/codefreak/project-r42catalog/env-r42catalog/lib/python2.7/site-packages/scrapy/selector/lxmldocument.pyc in __new__(cls, response, parser)
     25         if parser not in cache:
     26             obj = object_ref.__new__(cls)
---> 27             cache[parser] = _factory(response, parser)
     28         return cache[parser]
     29 

/home/codefreak/project-r42catalog/env-r42catalog/lib/python2.7/site-packages/scrapy/selector/lxmldocument.pyc in _factory(response, parser_cls)
     11 def _factory(response, parser_cls):
     12     url = response.url
---> 13     body = response.body_as_unicode().strip().encode('utf8') or '<html/>'
     14     parser = parser_cls(recover=True, encoding='utf8')
     15     return etree.fromstring(body, parser=parser, base_url=url)

错误：

AttributeError: 'Response' object has no attribute 'body_as_unicode'

我是否忽略了一些非常明显的东西或偶然发现了scrapy中的错误？

4

1 回答 1

9

body_as_unicode是TextResponse的一种方法。如果 http 响应包含文本内容，则 TextResponse 或其子类之一（例如 HtmlResponse）将由 scrapy 创建。

In [1]: fetch('http://scrapy.org')
...
In [2]: type(response)
Out[2]: scrapy.http.response.html.HtmlResponse
...
In [3]: fetch('http://www.scrapy.org/site-media/images/logo.png')
...
In [4]: type(response)
Out[4]: scrapy.http.response.Response

在您的情况下，最可能的解释是 scrapy 认为响应不包含文本。

来自服务器的 HTTP 响应是否正确设置了 Content-Type 标头？它是否在浏览器中正确呈现？这些问题将有助于了解这是预期的行为还是错误。

于 2013-01-19T17:03:38.180 回答