>>> from matplotlib.externals.six.moves.urllib.parse import urlparse
>>> urlparse(r'C:\Windows\notepad.exe').scheme
'c'

loading X:\Python35\lib\site-packages\matplotlib\mpl-data\sample_data\logo2.png
Traceback (most recent call last):
  File "watermark_image.py", line 12, in <module>
    im = image.imread(datafile)
  File "X:\Python35\lib\site-packages\matplotlib\image.py", line 1320, in imread
    fd = BytesIO(urlopen(fname).read())
  File "X:\Python35\lib\urllib\request.py", line 162, in urlopen
    return opener.open(url, data, timeout)
  File "X:\Python35\lib\urllib\request.py", line 465, in open
    response = self._open(req, data)
  File "X:\Python35\lib\urllib\request.py", line 488, in _open
    'unknown_open', req)
  File "X:\Python35\lib\urllib\request.py", line 443, in _call_chain
    result = func(*args)
  File "X:\Python35\lib\urllib\request.py", line 1310, in unknown_open
    raise URLError('unknown url type: %s' % type)
urllib.error.URLError: <urlopen error unknown url type: x>