we have a notion of a PassiveDefault which defines a "default" value on a table column, which can be a SQL function. As such, this function gets fired off upon insert, implicitly by the database, without an external pre-execution of that value.
however, SQL supports the embedding of functions as values in INSERT or UPDATE statements for the VALUES or SET clauses. SQLAlchemy currently cant really get a "func" or "text()" object directly into the VALUES of an insert (unless you write the whole insert by hand, of course), and it seems to work with UPDATE but puts some nasty parenthesis in there for no good reason (SQLite in particular really despises unnecessary parenthesis). lets get full blown support for whatever you want to put into an individual VALUES or SET clause (note this is a separate idea from INSERT from a SELECT, which doenst have a VALUES clause).