[web2py] View not serializing SELECT() - What am I missing?

[Cliff]

I cannot see what I'm doing wrong.

In the controller, I have functions like this:

def mk_select(rows):
  out = SELECT()
  for row in rows:
    out.append(row.somefield)
  return out

def edit():
  rows = get_rows()
  return dict(my_select=get_select(rows))

Then in the view, I do:
{{=my_select}}

But the browser shows:
(<gluon.html.SELECT object at 0x7fedc43b3d90>,) 

Surely this is not rocket science, but I cannot see the problem.  All help 
gratefully accepted.