title: convert a series of number to unique, random appearing string
body: <p>I have a sequence of decimal numbers (from 0 to 36^5), the goal is to get unique (non-repeating), random appearing strings composed 5 characters (uppercase and digits).</p>
  
  <p>e.g.</p>
  
  <pre><code>    1 get transformed to ACD1R
  
      2 get transformed to BD5T2
  </code></pre>
  
  <p>an essential condition is the generated strings appear to be random but underneath there's a bijective function between input and output of the transformation function.</p>
  
  <p>I have tried with base64, do you have any idea what's the pythonic cryptographic way, or the solution to this problem is not feasible</p>