title: Python sort strings alphabetically, lowercase first
body: <p>I want to sort a given array of strings alphabetically using python, but lowercase words should appear first.</p>
  
  <p>An example:</p>
  
  <pre><code>#!/usr/local/bin/python2.7
  arr=['A','e','a','D','f','B']
  arr.sort()
  for s in arr: print s
  </code></pre>
  
  <p>Input:</p>
  
  <pre><code>A
  e
  a
  D
  f
  B
  </code></pre>
  
  <p>Output (current):</p>
  
  <pre><code>A
  B
  D
  a
  e
  f
  </code></pre>
  
  <p>Output (should be):</p>
  
  <pre><code>a
  e
  f
  A
  B
  D
  </code></pre>