title: Running “import tensorflow” on Mac generates "No module named tensorflow" error
body: <p>Actually I already installed tensorflow by using</p>
  
  <pre><code>$ pip install tensorflow
  </code></pre>
  
  <p>and it works well when I use </p>
  
  <pre><code>$ python
  Python 2.7.15 (default, Jul 23 2018, 21:27:06) 
  [GCC 4.2.1 Compatible Apple LLVM 9.1.0 (clang-902.0.39.2)] on darwin
  Type "help", "copyright", "credits" or "license" for more information.
  &gt;&gt;&gt;import tensorflow
  &gt;&gt;&gt;
  </code></pre>
  
  <p>but when I use python3 on command line</p>
  
  <pre><code>Python 3.7.0 (v3.7.0:1bf9cc5093, Jun 26 2018, 23:26:24) 
  [Clang 6.0 (clang-600.0.57)] on darwin
  Type "help", "copyright", "credits" or "license" for more information.
  &gt;&gt;&gt; import tensorflow
  Traceback (most recent call last):
  File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  ModuleNotFoundError: No module named 'tensorflow'
  &gt;&gt;&gt; 
  </code></pre>
  
  <p>it shows an error, and it shows the same error when I use IDLE</p>