lxml question -- creating an etree.Element attribute with ':' in the name

[Stefan Behnel]

Burak Arslan, 18.09.2013 21:35:
> On 09/18/13 21:59, Roy Smith wrote:
>> I can create an Element with a 'foo' attribute by doing:
>>
>> etree.Element('my_node_name', foo="spam")
>>
>> But, how do I handle something like:
>>
>> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance", since "xmlns:xsi" isn't a valid python identifier?
> 
> xmlns: is a prefix with a special meaning: it defines an xml namespaces
> prefix. you should read about how they work.

Absolutely. For the specific case of a namespaced attribute, one way to do
it goes like this:

   el = etree.Element('my_node_name')
   el.set('{http://www.w3.org/2001/XMLSchema-instance}xsi', 'int')


> The following:
> 
> Element('{http://www.w3.org/2001/XMLSchema-instance}my_node_name')
> 
> will generate a proper xmlns declaration for you. It may not be the same
> every time, but it will do the job just as well.

For this specific namespace, and also a couple of other well-known
namespace URIs, lxml will use the "expected" prefix by default.

Stefan