无法在Jupyter Notebook中导入Tensorflow

我正在使用Jupyter Notebook并且正在尝试导入tensorflow。这是我得到的错误：

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

ModuleNotFoundError: No module named 'tensorflow'

我通过jupyter notebook在虚拟环境中键入来托管笔记本：

(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
>>> 

那么为什么找不到呢？jupyter在哪里寻找包裹？我什至在我的virtualenv之外安装了tensorflow。感谢您的帮助。