I'm not too familiar with Python but something like that would typically be handled by passing a pointer to a data structure containing the column data, and not each column itself (or does/did it have a 255-item limit on its other data structures too...?)

OK, but then you need to populate the data structure. You can do it with individual member assignments of course, but some quick Googling (I am not a Python expert either) suggests that the default row/object constructor for SQLAlchemy is an arg-per-field function.