subject_index
subject_index(anchored)Return the columns that identify a subject in this frame.
period_end travels with the subject when the caller kept it, so a method can reason about the period without going back to the panel.
Parameters
| Name | Type | Description | Default |
|---|---|---|---|
| anchored | pd.DataFrame | One row per subject and source. | required |
Returns
| Name | Type | Description |
|---|---|---|
| list[str] | The subject columns, followed by period_end when it is present. |