title: What type of result SQLAlchemy query() returns?
body: <p>I've got a table in my database</p>
  
  <pre><code>class Operator(db.Model):
      id = db.Column(db.Integer, primary_key=True)
      login = db.Column(db.String(100))
      calls = db.relationship('Call', backref='operator', lazy='dynamic')
  </code></pre>
  
  <p>and I want to get all <code>login</code> from this table. So I do</p>
  
  <pre><code>operators = db.session.query(models.Operator.login).all()
  print(operators)
  </code></pre>
  
  <p>And I suppose to get a list of <code>logins</code> but in fact I've got a list of tuples</p>
  
  <pre><code>[('ivanov',), ('petrov',)]
  </code></pre>
  
  <p>Of course I can manage this data but I can't understand why it's formatted in that way? Why it has empty second element in every tuple? Maybe I do something wrong and there is easier way to get list of <code>logins</code>?</p>