title: How to stop Python 2.7 running when "python3" is called in terminal?
body: <p>When I run python3 in terminal, it states that I am running Python 2.7.10. I updated a pip package and conda package and since I have no way of running python3. I am sure python 2 is running as writing 'print "hello"' works which is should not, if python3 successfully ran. </p>
  
  <pre><code>Daves-MBP:Desktop dave$ python3
  
  Python 2.7.10 (default, Oct  6 2017, 22:29:07) 
  [GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.31)] on darwin
  
  Type "help", "copyright", "credits" or "license" for more information.
  &gt;&gt;&gt; print "hello"
  hello
  </code></pre>
  
  <p>This should NOT work if python3 is running. 
  How can I get python3 running when I want to? 
  Do I need to set up the environment path, or something else?  </p>