Getting valueless elements in python lxml

I've been trying to use the lxml package's "objectify" to parse my XMLs and I've come across a problem. If I have a valueless tag, I can't seem to find a way to get its attributes.

For instance:

import lxml.objectify

xml_obj = lxml.objectify.fromstring("""
<A>
    <B foo="baz"/>
    <B foo="bar"/>
</A>""")
print xml_obj.getchildren()

A = None [ObjectifiedElement]
    B = u'' [StringElement]
      * baz = 'boo'
    B = u'' [StringElement]
      * foo = 'bar'

As you can see, the two B tags are turned into StringElement, but as seen when dumping the object, there should still be a way to retrieve the attributes!