title: how to take the same random key in a py dictionary?
body: <p>I want take random key in this dict :</p>
  <pre><code>{'F' : 'FF', 'B' : 'F[[-B][+B]]F[+FB]-B','B': 'F[-B]F[-FB]+B',}
  </code></pre>
  <p>I have same key this is normal and if the key is 'B' I want one of the two associated values to be returned to me.
  i.e. if the key is 'B' the result must be<code>'F[[-B][+B]]F[+FB]-B'</code>or<code>'F[-B]F[-FB]+B'</code>randomly
  and i didn't see how to make that.</p>