TypeError: unsupported operand type(s) for *: 'float' and 'NoneType'
<p>When I try to use  function inside another function</p>

<p><strong>Error</strong></p>

<blockquote>
  <p>TypeError: unsupported operand type(s) for *: 'float' and 'NoneType'</p>
</blockquote>

<pre><code># Function to calculate 2D circularity ratio      
def defineCircularRatio(perim2D, area2D): 

    circularity_ratio = (4*math.pi*area2D)/(perim2D**2)

    return circularity_ratio

    print "The 2D circul_ratio is:", circularity_ratio
</code></pre>

<p>perimeter and area  -calculated by other functions.</p>