Adding full traceback:

$ python yahoo_search.py
Traceback (most recent call last):
  File "yahoo_search.py", line 35, in <module>
    for result in search(query)['Result']:
  File "yahoo_search.py", line 28, in search
    result = json.load(urllib.request.urlopen(url))
  File "C:\Python30\lib\json\__init__.py", line 267, in load
    parse_constant=parse_constant, **kw)
  File "C:\Python30\lib\json\__init__.py", line 307, in loads
    return _default_decoder.decode(s)
  File "C:\Python30\lib\json\decoder.py", line 322, in decode
    raise ValueError(errmsg("Extra data", s, end, len(s)))
  File "C:\Python30\lib\json\decoder.py", line 30, in errmsg
    lineno, colno = linecol(doc, pos)
  File "C:\Python30\lib\json\decoder.py", line 21, in linecol
    lineno = doc.count('\n', 0, pos) + 1
TypeError: expected an object with the buffer interface