anaconda的scikit-learn报错It seems that scikit-learn has not been built

import sklearn  
Traceback (most recent call last):  
 File \"<stdin>\", line 1, in <module>  
  File \"sklearn/__init__.py\", line 37, in <module>  
    from . import __check_build  
  File \"sklearn/__check_build/__init__.py\", line 46, in <module>  
    raise_build_error(e)  
  File \"sklearn/__check_build/__init__.py\", line 41, in raise_build_error  
    %s\"\"\" % (e, local_dir, \'\'.join(dir_content).strip(), msg))  
ImportError: No module named _check_build  
___________________________________________________________________________  
Contents of sklearn/__check_build:  
__init__.py               __init__.pyc              _check_build.c  
_check_build.pyx          setup.py                  setup.pyc  
___________________________________________________________________________  
It seems that scikit-learn has not been built correctly.  
  
If you have installed scikit-learn from source, please do not forget  
to build the package before using it: run `python setup.py install` or  
`make` in the source directory.  
  
If you have used an installer, please check that it is suited for your  
Python version, your operating system and your platform.