2015-06-22 65 views
2

值我想:属性集而不LXML XML

<div data-a> 

但LXML API似乎给我的只有这一点:

<div data-a=''> 

我如何获得价值少的属性?


令人讨厌的是,空值和空值由LXML表示为空字符串。

设置None值没有帮助。

In [19]: from lxml.html import fromstring, tostring 

In [20]: b = fromstring('<body class="meow" data-a="haha" data-b data-x="">text-fef27e87389e466fb99b5421629323f6</body>') 

In [21]: b.attrib 
Out[21]: {'data-a': 'haha', 'data-x': '', 'data-b': '', 'class': 'meow'} 

In [22]: b = fromstring('<body class="meow" data-a="haha" data-b data-x="">text-fef27e87389e466fb99b5421629323f6</body>') 

In [23]: b.attrib 
Out[23]: {'data-a': 'haha', 'data-x': '', 'data-b': '', 'class': 'meow'} 

In [24]: b.attrib['data-y'] = None 
--------------------------------------------------------------------------- 
TypeError         Traceback (most recent call last) 
<ipython-input-24-1f55133e3dc4> in <module>() 
----> 1 b.attrib['data-y'] = None 

/usr/lib/python2.7/dist-packages/lxml/etree.so in lxml.etree._Attrib.__setitem__ (src/lxml/lxml.etree.c:58775)() 

/usr/lib/python2.7/dist-packages/lxml/etree.so in lxml.etree._setAttributeValue (src/lxml/lxml.etree.c:19025)() 

/usr/lib/python2.7/dist-packages/lxml/etree.so in lxml.etree._utf8 (src/lxml/lxml.etree.c:26460)() 

TypeError: Argument must be bytes or unicode, got 'NoneType' 


tag.attrib['data-a'] = None 
TypeError: Argument must be bytes or unicode, got 'NoneType' 
+0

请出示一个示范最少的代码。 [问] – boardrider

回答

2

恕我直言,lxml表明预期的行为。属性没有价值,使非格式良好的XML,以及体面的XML解析器不产生非格式良好的XML:

+0

所以坏消息是我需要LXML的替代品吗? – aitchnyu

+0

也许您可以为属性指定一个唯一值,以便稍后可以轻松地找到并用简单的字符串操作替换该属性(保持使用lxml,但构造无值属性除外) – har07