[sqlalchemy] relationsip(): In Parent or Child Class?

[Rich Shepard]

  There are a number of many-to-one table/class relationships in the
application. In the many class I use ForeignKey() to relate that column to
the appropriate 'one' class and column.

  Reading the ORM tutorial tells me that the relationship() function can be
in either table. I can specify the backref from the many class to the one
class or define it as a child in the one class with the backref to the many
class.

  Is one placement preferred over the other? If not, what criteria are used
to determine where the relationship() function should be placed?

Rich