title: How to perform a pairwise swap of a list?
body: <p>I want to write a small code in python that Swap Elements in a list this program will accept a list, and will return a list that exchanges the positions of each pair of adjacent elements: positions 0 and 1, positions 2 and 3, and so on.  If the list has an odd number of elements, then the element in the last position stays “in place”.</p>
  
  <pre><code>Before: [1,2,3,4,5]
  After: [2,1,4,3,5]
  </code></pre>
  
  <p>This looks unpythonic. What is the Python way to do it?</p>