title: How to give column list for select statement in sqlalchemy?
body: <p>below code is for select "country", "gender" from "Message" where ~</p>
  
  <pre><code>    users = session.query(
          Message.country,
          Message.gender,
      ).filter(
          Message.date_joined.between(begin_date, end_date),
      ).all()
  </code></pre>
  
  <p>when I try sql with this</p>
  
  <pre><code>    columns = (
          Message.country,
          Message.gender,
      )
  
      users = session.query(
          columns
      ).filter(
          Message.date_joined.between(begin_date, end_date),
      ).all()
  </code></pre>
  
  <p>I got error</p>
  
  <pre><code>sqlalchemy.exc.InvalidRequestError: SQL expression, column, or mapped entity expected - got '(&lt;sqlalchemy.orm.attributes.InstrumentedAttribute object at 0x117f215c8&gt;, &lt;sqlalchemy.orm.attributes.InstrumentedAttribute object at 0x117f21518&gt;)'
  </code></pre>
  
  <p>I thought if i gave parameter as tuple, would be possible however there was exception.</p>
  
  <p>How can I give columns as variable for query?</p>