Traceback (most recent call last):
  File "/Users/kevin.dasilva/SQL_tings/SQL_ingest.py", line 103, in <module>
    sess.add_all(objs)
  File "/Users/kevin.dasilva/SQL_tings/SQL_env/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 1785, in add_all
    self.add(instance, _warn=False)
  File "/Users/kevin.dasilva/SQL_tings/SQL_env/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 1776, in add
    self._save_or_update_state(state)
  File "/Users/kevin.dasilva/SQL_tings/SQL_env/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 1795, in _save_or_update_state
    halt_on=self._contains_state):
  File "/Users/kevin.dasilva/SQL_tings/SQL_env/lib/python3.6/site-packages/sqlalchemy/orm/mapper.py", line 2870, in cascade_iterator
    visited_states, halt_on))
  File "/Users/kevin.dasilva/SQL_tings/SQL_env/lib/python3.6/site-packages/sqlalchemy/orm/relationships.py", line 1591, in cascade_iterator
    c.__class__