无法在Jupyter笔记本中导入tensorflow

我正在使用Jupyter笔记本,我正在尝试导入tensorflow。下面是我得到的错误:

---------------------------------------------------------------------------
ModuleNotFoundError                       Traceback (most recent call last)
<ipython-input-15-64156d691fe5> in <module>()
----> 1 import tensorflow as tf

ModuleNotFoundError: No module named 'tensorflow'

我正在通过键入 jupyter notebook 在我的虚拟环境中:

(labs) Sahands-MBP:part1 sahandzarrinkoub$ jupyter notebook

tensorflow肯定安装在虚拟环境中:

(labs) Sahands-MBP:part1 sahandzarrinkoub$ python
Python 3.6.4 |Anaconda, Inc.| (default, Jan 16 2018, 12:04:33) 
[GCC 4.2.1 Compatible Clang 4.0.1 (tags/RELEASE_401/final)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import tensorflow
>>> 

那为什么找不到呢?jupyter在哪里寻找包裹?我甚至在我的virtualenv之外安装了tensorflow。