title: sqlalchemy: Why create a sessionmaker before assign it to a Session object?
body: <p>Why I always need to do that in 2 steps in SqlAlchemy?</p>
  
  <pre><code>import sqlalchemy as sa
  import sqlalchemy.orm as orm
  
  engine = sa.create_engine(&lt;dbPath&gt;, echo=True)
  Session = orm.sessionmaker(bind=engine)
  my_session = Session()
  </code></pre>
  
  <p>Why I cannot do it in one shot like (it's could be more simple, no?) : </p>
  
  <pre><code>import sqlalchemy as sa
  import sqlalchemy.orm as orm
  
  engine = sa.create_engine(&lt;dbPath&gt;, echo=True)
  Session = orm.Session(bind=engine)
  </code></pre>