title: Calculate years + months + days between 2 dates?
body: <p>I have 2 person's birth information, I want to do some analysis on them.
  Like, the difference between their age, seconds, years+months+days.
  I tried this:</p>
  
  <pre><code>from datetime import date
  a = date(1991, 07, 20)
  b = date(1999, 06, 06)
  print((a-b).days)
  -2878
  </code></pre>
  
  <p>this gives me <code>2878</code> days, but i want to calculate <code>years + months + days</code>
  i tried to divide 2878/365, but i want the exact calculations
  How can i approach this?</p>
  
  <p>Expected Output:</p>
  
  <pre><code>7 years x months x days
  </code></pre>