title: python sqlalchemy label usage
body: <p>I know I can use the label method for alias, but I can't figure out how to use the labeled element later in the query - something like the following:</p>
  
  <pre><code>session.query(Foo.bar.label("foobar")).filter(foobar &gt; 10).all()
  </code></pre>
  
  <p>Of course, this doesn't work since there is no variable called foobar. How could this be accomplished?</p>
  
  <p>(The over simplified example was just for easy comprehension...)</p>