I'm looking for a complete example of using select for update in SQLAlchemy, but haven't found one googling. I need to lock a single row and update a column, the following code doesn't work (blocks forever):

s = table.select(table.c.user=="test",for_update=True)
u = table.update().where(table.c.user=="test")         
u.execute(email="foo") 

Do I need a commit? How do I do that? As far as I know you need to: begin transaction select ... for update update commit