title: negative pow in python
body: <p>I have this problem  </p>
  
  <pre><code>&gt;&gt;&gt; import math
  &gt;&gt;&gt; math.pow(-1.07,1.3)  
  Traceback (most recent call last):  
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;  
  ValueError: math domain error
  </code></pre>
  
  <p>any suggestion ? </p>