a.__init__.py

from __future__ import unicode_literals

from .b import Foo

__all__ = ['Foo']

a.b.py

class Foo(object):
    pass

gistfile1.txt

Python 2.7.10 (default, Jun 10 2015, 19:42:47) 
[GCC 4.2.1 Compatible Apple LLVM 6.1.0 (clang-602.0.53)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from a import *
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: Item in ``from list'' not a string