Featuretools与非唯一联接键的关系

如果表中没有可以用作唯一索引的列,可以让featuretools自动创建一个。打电话的时候 EntitySet.entity_from_dataframe(...) index 参数和设置 make_index=True

例如,在下面的代码中 event_id 索引将自动创建

import pandas as pd
import featuretools as ft

df = pd.DataFrame({"customer_id": [0, 1, 0, 1, 1],
                   "date": [pd.Timestamp("1/1/2018"), pd.Timestamp("1/1/2018"),
                            pd.Timestamp("1/1/2018"), pd.Timestamp("1/2/2018"),
                            pd.Timestamp("1/2/2018")],
                   "event_type": ["view", "purchase", "view", "cancel", "purchase"]})

es = ft.EntitySet(id="customer_events")                
es.entity_from_dataframe(entity_id="events",
                         dataframe=df,
                         index="event_id",
                         make_index=True,
                         time_index="date")

print(es["events"])

在events实体中,您可以看到event\ id现在是一个变量,即使它不在原始数据帧中

Entity: events
  Variables:
    event_id (dtype: index)
    date (dtype: datetime_time_index)
    customer_id (dtype: numeric)
    event_type (dtype: categorical)
  Shape:
    (Rows: 5, Columns: 4)