JSON encoder that can handle simple lxml objectify types, based on the original: https://gist.github.com/aisipos/345559, extended to accommodate encoding child nodes with the same tag name as a list.

ObjectifyJSONEncoder.py

import json
import lxml
from lxml import objectify

class ObjectifyJSONEncoder(json.JSONEncoder):
    """ JSON encoder that can handle simple lxml objectify types,
        based on the original: https://gist.github.com/aisipos/345559, extended
        to accommodate encoding child nodes with the same tag name as a list.

        Usage:

        >>> import json
        >>> import lxml
        >>> from lxml import objectify
        >>> obj = objectify.fromstring("<author><name>W. Shakespeare</name><play>Twelfth Night</play><play>As You Like It</play></author>")
        >>> json.dumps(obj, cls=ObjectifyJSONEncoder)
        '{"play": ["Twelfth Night", "As You Like It"], "name": "W. Shakespeare"}'

    """
    def default(self, o):
        if isinstance(o, lxml.objectify.IntElement):
            return int(o)
        if isinstance(o, lxml.objectify.NumberElement) or isinstance(o, lxml.objectify.FloatElement):
            return float(o)
        if isinstance(o, lxml.objectify.ObjectifiedDataElement):
            return str(o)
        if hasattr(o, '__dict__'):
            # objectify elements act like dicts to allow access to child nodes
            # via their tag name.  If an element has more than one child of the
            # same name the dict only contains the first value against the tag
            # name; to ensure all children are encoded create a list of child
            # node values and assign it to the key that matches their tag name.
            d = o.__dict__.copy()
            for k in d.keys():
                if len(d[k]) > 1:
                    d[k] = [i for i in d[k]]
            return d
        return json.JSONEncoder.default(self, o)