Python Scrapy：从HTML脚本中提取JSON_Python_Html_Json_Xpath_Scrapy

Python Scrapy：从HTML脚本中提取JSON

python html json xpath scrapy

Python Scrapy：从HTML脚本中提取JSON,python,html,json,xpath,scrapy,Python,Html,Json,Xpath,Scrapy,我试图从HTML脚本中提取（看起来是）JSON数据。网站上的HTML脚本如下所示： <script> $(document).ready(function(){ var terms = new Verba.Compare.Collections.Terms([{"id":"6436","name":"SUMMER 16","inquiry":true,"ordering":true},{"id":"6517","name":"FALL 16","inquiry":t

我试图从HTML脚本中提取（看起来是）JSON数据。网站上的HTML脚本如下所示：

<script>
  $(document).ready(function(){
    var terms    = new Verba.Compare.Collections.Terms([{"id":"6436","name":"SUMMER 16","inquiry":true,"ordering":true},{"id":"6517","name":"FALL 16","inquiry":true,"ordering":true}]);
    var view     = new Verba.Compare.Views.CourseSelector({el: "body", terms: terms});
  });
</script>

使用下面的代码，我能够得到完整的脚本

    def parse(self, response):
        print response.xpath('/html/body/script[2]').extract()

是否有一种简单的方法可以从该脚本中提取“id”、“name”等值。或者，有没有更直接的方法修改xpath？我似乎无法使用firebug对xpath进行更深入的研究。

您无法“深入”，因为该元素的内容只是文本。从JavaScript读取JSON并不难：

line = javascript.strip().splitlines()[1]
the_json = line.split('(', 1)[1].split(')', 1)[0]

我将使用正则表达式提取它，类似于：

response.xpath('/html/body/script[2]').re_first('\((\[.*\])\)')

你可以用这个

为了举例说明，首先，让我们使用示例HTML创建一个Scrapy选择器，并获取JavaScript语句：

>>> import scrapy
>>> sample = '''<script>
...   $(document).ready(function(){
...     var terms    = new Verba.Compare.Collections.Terms([{"id":"6436","name":"SUMMER 16","inquiry":true,"ordering":true},{"id":"6517","name":"FALL 16","inquiry":true,"ordering":true}]);
...     var view     = new Verba.Compare.Views.CourseSelector({el: "body", terms: terms});
...   });
... </script>'''
>>> selector = scrapy.Selector(text=sample, type='html')
>>> selector.xpath('//script//text()').extract_first()
u'\n  $(document).ready(function(){\n    var terms    = new Verba.Compare.Collections.Terms([{"id":"6436","name":"SUMMER 16","inquiry":true,"ordering":true},{"id":"6517","name":"FALL 16","inquiry":true,"ordering":true}]);\n    var view     = new Verba.Compare.Views.CourseSelector({el: "body", terms: terms});\n  });\n'

最后，现在您有了

元素，您可以将它传递到

js2xml.jsonlike.make_dict（）

以获得一个好的Python对象来使用（

make_dict

有点命名错误）：

注意：您还可以使用快捷方式

js2xml.jsonlike.getall（）

获取所有看起来像Python dict或list的内容（您得到两个列表，您对第一个列表感兴趣）：

提供将JavaScript对象解析为dict的API

例如，如果JavaScript代码包含

var data={field:“value”，secondField:“second value”}

；您可以按如下方式提取该数据：

import chompjs
javascript = response.css('script::text').get()
data = chompjs.parse_js_object(javascript)

最终结果是

{'field'：'value'，'secondField'：'secondvalue'}

这会有帮助吗：它有效！经过更多的研究，我找到了一个类似于你刚才发布的方法。不过，你的要干净得多。谢谢，非常欢迎。如果它解决了您的问题，请随时将此标记为答案。

>>> import js2xml
>>> jssnippet = selector.xpath('//script//text()').extract_first()
>>> jstree = js2xml.parse(jssnippet)
>>> jstree
<Element program at 0x7fc7c6bae1b8>

>>> print(js2xml.pretty_print(jstree))
<program>
  <functioncall>
    <function>
      <dotaccessor>
        <object>
          <functioncall>
            <function>
              <identifier name="$"/>
            </function>
            <arguments>
              <identifier name="document"/>
            </arguments>
          </functioncall>
        </object>
        <property>
          <identifier name="ready"/>
        </property>
      </dotaccessor>
    </function>
    <arguments>
      <funcexpr>
        <identifier/>
        <parameters/>
        <body>
          <var name="terms">
            <new>
              <dotaccessor>
                <object>
                  <dotaccessor>
                    <object>
                      <dotaccessor>
                        <object>
                          <identifier name="Verba"/>
                        </object>
                        <property>
                          <identifier name="Compare"/>
                        </property>
                      </dotaccessor>
                    </object>
                    <property>
                      <identifier name="Collections"/>
                    </property>
                  </dotaccessor>
                </object>
                <property>
                  <identifier name="Terms"/>
                </property>
              </dotaccessor>
              <arguments>
                <array>
                  <object>
                    <property name="id">
                      <string>6436</string>
                    </property>
                    <property name="name">
                      <string>SUMMER 16</string>
                    </property>
                    <property name="inquiry">
                      <boolean>true</boolean>
                    </property>
                    <property name="ordering">
                      <boolean>true</boolean>
                    </property>
                  </object>
                  <object>
                    <property name="id">
                      <string>6517</string>
                    </property>
                    <property name="name">
                      <string>FALL 16</string>
                    </property>
                    <property name="inquiry">
                      <boolean>true</boolean>
                    </property>
                    <property name="ordering">
                      <boolean>true</boolean>
                    </property>
                  </object>
                </array>
              </arguments>
            </new>
          </var>
          <var name="view">
            <new>
              <dotaccessor>
                <object>
                  <dotaccessor>
                    <object>
                      <dotaccessor>
                        <object>
                          <identifier name="Verba"/>
                        </object>
                        <property>
                          <identifier name="Compare"/>
                        </property>
                      </dotaccessor>
                    </object>
                    <property>
                      <identifier name="Views"/>
                    </property>
                  </dotaccessor>
                </object>
                <property>
                  <identifier name="CourseSelector"/>
                </property>
              </dotaccessor>
              <arguments>
                <object>
                  <property name="el">
                    <string>body</string>
                  </property>
                  <property name="terms">
                    <identifier name="terms"/>
                  </property>
                </object>
              </arguments>
            </new>
          </var>
        </body>
      </funcexpr>
    </arguments>
  </functioncall>
</program>

>>> jstree.xpath('//var[@name="terms"]')
[<Element var at 0x7fc7c565e638>]
>>> jstree.xpath('//var[@name="terms"]/new/arguments/*')
[<Element array at 0x7fc7c565e5a8>]
>>> jstree.xpath('//var[@name="terms"]/new/arguments/*')[0]
<Element array at 0x7fc7c565e5a8>

>>> js2xml.jsonlike.make_dict(jstree.xpath('//var[@name="terms"]/new/arguments/*')[0])
[{'ordering': True, 'inquiry': True, 'id': '6436', 'name': 'SUMMER 16'}, {'ordering': True, 'inquiry': True, 'id': '6517', 'name': 'FALL 16'}]
>>>

>>> js2xml.jsonlike.getall(jstree)
[[{'ordering': True, 'inquiry': True, 'id': '6436', 'name': 'SUMMER 16'}, {'ordering': True, 'inquiry': True, 'id': '6517', 'name': 'FALL 16'}], {'el': 'body', 'terms': 'terms'}]

import chompjs
javascript = response.css('script::text').get()
data = chompjs.parse_js_object(javascript)