title: Error importing scipy.special.expit
body: <p>I want to import the sigmoid function available at <code>scipy.special.expit</code>.</p>
  
  <p>If I use <code>import scipy.special.expit as sigmoid</code> (or without the "as sigmoid") I get a "No module called expit" error.</p>
  
  <p>If I use <code>from scipy import special</code>, then using <code>special.expit(N)</code> <strong>works</strong>.</p>
  
  <p>If I use <code>from scipy import special.expit as sigmoid</code>, invalid syntax at <code>special.expit</code> (the dot).</p>
  
  <p>If I use <code>from scipy.special import expit</code>, <code>special</code> is not defined error.</p>
  
  <p>So... how the hell can I import the <code>expit</code>function assigning the "sigmoid" alias? </p>