ipython notebook 不能导入numpy

我在server上安装了ipython notebook。启动后import numpy报如下异常：

---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
 in ()
----> 1 import numpy

/home/users/kuangzhexi/.jumbo/lib/python2.7/site-packages/numpy/__init__.py in ()
151         return loader(*packages, **options)
152 
--> 153     from . import add_newdocs
154     __all__ = ['add_newdocs', 'ModuleDeprecationWarning']
155 

/home/users/kuangzhexi/.jumbo/lib/python2.7/site-packages/numpy/add_newdocs.py in ()
 11 from __future__ import pision, absolute_import, print_function
 12 
---> 13 from numpy.lib import add_newdoc
 14 
 15 ###############################################################################

/home/users/kuangzhexi/.jumbo/lib/python2.7/site-packages/numpy/lib/__init__.py in ()
 15 from .ufunclike import *
 16 
---> 17 from . import scimath as emath
 18 from .polynomial import *
 19 #import convertcode

ImportError: cannot import name scimath

我看了stackoverflow如下两个答案：
http://stackoverflow.com/questions/26238004/ipython-notebook-throws-importerror-ipython-doesnt
http://stackoverflow.com/questions/15514593/importerror-no-module-named-when-trying-to-run-python-script/15622021#15622021
我的操作是：
sys.path.append('/home/users/kuangzhexi/.jumbo/lib/python2.7/site-packages/numpy/lib')
sys.path.append('/home/users/kuangzhexi/.jumbo/lib/python2.7/site-packages/numpy/')
但是还是不行。