改变属性值

Question

这里是我的xml：

<request><table attributeA="50" attributeB="1"></table>........</request> 

我怎么更新attributeA的价值，有一些像attributeA = “456”

<request><table attributeA="456" attributeB="1"></table>........</request> 

Answer 1

使用etree和XPath ：

>>> from lxml import etree 
>>> xml = '<request><table attributeA="50" attributeB="1"></table></request>' 
>>> root = etree.fromstring(xml) 
>>> for el in root.xpath("//table[@attributeA]"): 
...  el.attrib['attributeA'] = "456" 
... 
>>> print etree.tostring(root) 
<request><table attributeA="456" attributeB="1"/></request>