title: How to convert list of tuples to dict without losing order
body: <p>I want to count the letter frequency in a string using Dict, sorted in alphabetical order. The output should be a dictionary only.</p>
  
  <p>Here's my attempt.</p>
  
  <pre><code>    s = raw_input()
      arr = {}
      for i in s :
          if i in arr :
              arr[i] += 1
          else :
              arr[i] = 1
      x = sorted(arr.items())
      print dict(x)
  </code></pre>
  
  <p>Input :</p>
  
  <pre><code>amphisofttechnologies
  </code></pre>
  
  <p>Expected Output :</p>
  
  <pre><code>{'a': 1, 'c': 1, 'e': 2, 'f': 1, 'g': 1, 'h': 2, 'i': 2, 'l': 1, 'm': 1, 'n': 1, 'o': 3, 'p': 1, 's': 2, 't': 2}
  </code></pre>
  
  <p>My Output :</p>
  
  <pre><code>{'a': 1, 'c': 1, 'e': 2, 'g': 1, 'f': 1, 'i': 2, 'h': 2, 'm': 1, 'l': 1, 'o': 3, 'n': 1, 'p': 1, 's': 2, 't': 2}
  </code></pre>
  
  <p>Kindly point out where I am making the mistake.</p>