title: sampling random floats on a range in numpy
body: <p>How can I sample random floats on an interval [a, b] in numpy? Not just integers, but any real numbers. For example,</p>
  
  <p><code>random_float(5, 10)</code> </p>
  
  <p>would return random numbers between <code>[5, 10]</code>. thanks.</p>