ImportError in importing from sklearn: cannot import name check_build

Worked for me after installing scipy.

>>> from sklearn import preprocessing, metrics, cross_validation

Traceback (most recent call last):
  File "<pyshell#6>", line 1, in <module>
    from sklearn import preprocessing, metrics, cross_validation
  File "D:\Python27\lib\site-packages\sklearn\__init__.py", line 31, in <module>
    from . import __check_build
ImportError: cannot import name __check_build
>>> ================================ RESTART ================================
>>> from sklearn import preprocessing, metrics, cross_validation
>>> 

So, simply try to restart the shell!

My solution for Python 3.6.5 64-bit Windows 10:

1. pip uninstall sklearn
2. pip uninstall scikit-learn
3. pip install sklearn

No need to restart command-line but you can do this if you want. It took me one day to fix this bug. Hope this help.