Should '% ' be identified as a '%' or should it throw an error?

[jwp]

Per the sqlalchemy test failures pointed out by Kevin:

'SELECT flds.intcol % %(intcol_1)s AS anon_1 \nFROM flds ORDER BY flds.idcol' {'intcol_1': 3}

The paramstyle code expects %% to be used to represent %.