title: Swapping numbers before and after decimal
body: <p>I'm writing a function that takes a <strong>positive number</strong> and swaps the numbers before and after the decimal point and returns that as a <strong>string</strong>. If the input is an integer then the returned string starts with '0.' i.e. 37 -&gt; 0.37</p>
  <pre class="lang-py prettyprint-override"><code>def float_swap(x):
      a = x - int(x)
      b = int(x)
      return str(b+a)
  
  print(float_swap(2.5))
  # 2.5 
  </code></pre>
  <p>Where am I going wrong here?</p>