2015-06-22 64 views
2

值我想:屬性集而不LXML XML

<div data-a> 

但LXML API似乎給我的只有這一點:

<div data-a=''> 

我如何獲得價值少的屬性?


令人討厭的是,空值和空值由LXML表示爲空字符串。

設置None值沒有幫助。

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

請出示一個示範最少的代碼。 [問] – boardrider

回答

2

恕我直言,lxml表明預期的行爲。屬性沒有價值,使非格式良好的XML,以及體面的XML解析器不產生非格式良好的XML:

+0

所以壞消息是我需要LXML的替代品嗎? – aitchnyu

+0

也許您可以爲屬性指定一個唯一值,以便稍後可以輕鬆地找到並用簡單的字符串操作替換該屬性(保持使用lxml,但構造無值屬性除外) – har07