I have python code that uses mechanize to login to a website. With six==1.4.1 and six==1.10.0, I get this error:

Traceback (most recent call last):
  File "scrapeRecipe.py", line 31, in <module>
    br.select_form(name="aspnetForm")
  File "/Library/Python/2.7/site-packages/mechanize/_mechanize.py", line 619, in select_form
    global_form = self._factory.global_form
  File "/Library/Python/2.7/site-packages/mechanize/_html.py", line 260, in global_form
    self.forms()
  File "/Library/Python/2.7/site-packages/mechanize/_html.py", line 267, in forms
    self._current_forms, self._current_global_form = self._get_forms()
  File "/Library/Python/2.7/site-packages/mechanize/_html.py", line 282, in _get_forms
    if self.root is None:
  File "/Library/Python/2.7/site-packages/mechanize/_html.py", line 247, in root
    response, verify=False))
  File "/Library/Python/2.7/site-packages/mechanize/_html.py", line 145, in content_parser
    from html5lib import parse
  File "/Library/Python/2.7/site-packages/html5lib/__init__.py", line 16, in <module>
    from .html5parser import HTMLParser, parse, parseFragment
  File "/Library/Python/2.7/site-packages/html5lib/html5parser.py", line 2, in <module>
    from six import with_metaclass, viewkeys, PY3
ImportError: cannot import name viewkeys

This appears to similar to this post, except changing the version of six package didn't fix anything.