try:
    import xml.etree.ElementTree as ET # in python >=2.5
except ImportError:
    try:
        import cElementTree as ET # effbot's C module
    except ImportError:
        try:
            import elementtree.ElementTree as ET # effbot's pure Python module
        except ImportError:
            try:
                import lxml.etree as ET # ElementTree API using libxml2
            except ImportError:
                import warnings
                warnings.warn("could not import ElementTree "
                              "(http://effbot.org/zone/element-index.htm)")
                # Or you might just want to raise an ImportError here.

# Use ET.Element, ET.ElementTree, etc...