I needed to delete records from a PostgreSQL table that has descendant tables related by foreign keys. Some tables have multiple foreign keys which complicates the matter. Here's the pseudo code to do it:

def delete_records(table, parent_tables=[]):
    "Pseudo code to delete all records from a table and its descendants"
    parent_tables.append(table)
    for child in child_tables(table):
        delete_it = True
        for fkey in foreign_keys_from(child):
            if not (fkey.f_table in parent_tables):
                delete_it = False
                break

        if delete_it:
            delete_records(child)
    execute_sql("DELETE FROM %s" % table)