from item import Item
from lxml.html import fromstring

class SomeStructure(Item):
    id = IntegerField('//path/to/@id')
    name = StringField('//path/to/name')
    date = DateTimeField('//path/to/@datetime', '%Y-%m-%d %H:%M:%S')

structure = SomeStructure(fromstring(SOME_HTML))
print(structure.id)
print(structure.name)
print(structure.date)