How to add multiple relationships to a new entity? - featuretools

Question

I am trying to add multiple relationships simultaneously to an entityset that i created. I use the following code:
import featuretools as ft
data = ft.demo.load_mock_customer()
customers_df = data["customers"]
sessions_df = data["sessions"]
transactions_df = data["transactions"]
entities = {
"customers" : (customers_df, "customer_id"),
"sessions" : (sessions_df, "session_id", "session_start"),
"transactions" : (transactions_df, "transaction_id", "transaction_time")}
es = ft.EntitySet('es',entities=entities)
relationships = [("sessions", "session_id", "transactions", "session_id"),
("customers", "customer_id", "sessions", "customer_id")]
es.add_relationships(relationships)
It throws AttributeError: 'tuple' object has no attribute 'child_entity'. Is this way to add multiple entities to an entityset correct (i think it is correct if i am reading the official doc correctly) or am i missing something?

Answer 1

The input to add_relationships must be a list of relationship objects. This is how you would add the relationships to the entity set:
relationships = []
parent = es["sessions"]["session_id"]
child = es["transactions"]["session_id"]
relationship = ft.Relationship(parent, child)
relationships.append(relationship)
parent = es["customers"]["customer_id"]
child = es["sessions"]["customer_id"]
relationship = ft.Relationship(parent, child)
relationships.append(relationship)
es.add_relationships(relationships)
As an alternative, you can directly construct an entity set with the relationships.
relationships = [(
"sessions",
"session_id",
"transactions",
"session_id",
), (
"customers",
"customer_id",
"sessions",
"customer_id",
)]
es = ft.EntitySet(
id='es',
entities=entities,
relationships=relationships,
)
Let me know if this helps.