title: How to clean the workspace in python?
body: <p>After I import some functions from a module</p>
  
  <pre><code>&gt;&gt;&gt; from math import pi, e, sin, cos
  &gt;&gt;&gt; dir()
  ['__builtins__', '__doc__', '__name__', '__package__', 'cos', 'e', 'pi', 'sin']
  </code></pre>
  
  <p>Can I clean the workspace? I mean, other than manually like </p>
  
  <pre><code>&gt;&gt;&gt; del pi, e, sin, cos
  &gt;&gt;&gt; dir()
  ['__builtins__', '__doc__', '__name__', '__package__']
  </code></pre>
  
  <p>Something like the matlab/octave <code>clear</code>?</p>