line 170 of __init__.py revision 11 raises a UnicodeEncodeError exception for some of my constant contact data.
I changed it from:
xml = ET.fromstring(response['body'])
xml = ET.fromstring(response['body'].encode('ascii','xmlcharrefreplace'))
and that subdues the exception. It depends on how the library is being used whether this is a sufficient fix, I'd guess. Attached is my change.