>>> import xml.etree.cElementTree as ET
>>> tree = ET.parse('test.xml')
>>> root = tree.getroot()
>>> dir(root)
['!__reduce__', '__class__', '__copy__', '__deepcopy__', '__delattr__', '__delitem__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__gt__', '__hash__', '__init__', '__le__', '__len__', '__lt__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__setitem__', '__sizeof__', '__str__', '__subclasshook__', 'append', 'clear', 'find', 'findall', 'findtext', 'get', 'getchildren', 'getiterator', 'insert', 'items', 'keys', 'makeelement', 'remove', 'set']
>>> root.tag
'{http://testnamespace}root'

The tag property is not listed in dir() making ElementTree more difficult to use for those of us with poor memories.

Confirmed.

As a workaround, the Python implementation shows its attributes "tag", "text", "tail", "attrib".

Since upstream version of ElementTree drops support for Python < 2.3, we may refactor the Element type, and use the "tp_members" and "tp_getset" slots.

Attached a patch with test for this:

Following the suggestion, I put "tag", "text", "tail", and "attrib" to be accessible via tp_getset for _etree.Element type.

Is this a right approach? I converted the hard-coded "attributes" into real, C-API attributes.

It looks right to me, but I would include more verbose pydoc strings.  

IE, "The tail attribute can be used to hold additional data associated with the element" tells me nothing.  You could explain here what .tail actually is, a few XML examples of what would be put in tail or what tail would become, and the API design reason why tail is used in addition to text.