title: SQLALchemy: TypeError: bad operand type for abs(): 'BinaryExpression'
body: <p>I am trying to convert the SQL command <code>select * from chart where abs(jupiter_lon-h5_lon) &lt; 0.88</code> into SQLAlchemy:</p>
  <p><code>db.session.query(Chart).filter(abs(Chart.jupiter_lon - Chart.h5_lon) &lt; 0.88).all()</code></p>
  <p>but I'm getting the error: TypeError: bad operand type for abs(): 'BinaryExpression' - which I don't understand. What's wrong here?</p>