title: How do I allow a user to input vectors rather than strings?
body: <p>I'm trying to make my program allow the user to input vectors of the form (x,y,z) using python's built in input() function.</p>
  
  <p>If entered normally in python with out using the input() function it indexes each vector separately. For example,</p>
  
  <pre><code>&gt;&gt;&gt; z = (1,2,3), (4,5,6), (7,8,9)
  &gt;&gt;&gt; z[1]
  (4, 5, 6)
  </code></pre>
  
  <p>But when I try to use the input function I run into the following problem.</p>
  
  <pre><code>&gt;&gt;&gt; z = input('What are the vectors?  ')
  What are the vectors?  (1,2,3), (4,5,6), (7,8,9)
  &gt;&gt;&gt; z[1]
  '1'
  </code></pre>
  
  <p>Why does using the input function turn it into a string and is there a way around this?</p>
  
  <p>Thanks</p>