> ## Documentation Index
> Fetch the complete documentation index at: https://docs.activeviam.com/llms.txt
> Use this file to discover all available pages before exploring further.

# atoti.SiblingsScope

### *final class* atoti.SiblingsScope

Scope performing a “siblings” aggregation.

The aggregated value for each member of a given level in [`hierarchy`](#atoti.SiblingsScope.hierarchy) is computed by aggregating all the members with the same parents (i.e. its siblings) with the given function.

A siblings aggregation is appropriate for operations such as marginal aggregations (e.g. marginal VaR, marginal mean) for non-linear aggregation functions.

### Example

Using this scope with [`atoti.agg.sum()`](./atoti.agg.sum#atoti.agg.sum) to perform a “siblings” sum:

```pycon theme={"languages":{"custom":["/engine/python-sdk/0.9/languages/pycon.tmLanguage.json"]}}
>>> from datetime import date
>>> df = pd.DataFrame(
...     columns=["Date", "Quantity"],
...     data=[
...         (date(2019, 7, 1), 15),
...         (date(2019, 7, 2), 20),
...         (date(2019, 7, 3), 30),
...         (date(2019, 6, 1), 25),
...         (date(2019, 6, 2), 15),
...         (date(2018, 7, 1), 5),
...         (date(2018, 7, 2), 10),
...         (date(2018, 6, 1), 15),
...         (date(2018, 6, 2), 5),
...     ],
... )
>>> table = session.read_pandas(df, table_name="Siblings")
>>> cube = session.create_cube(table, mode="manual")
>>> h, l, m = cube.hierarchies, cube.levels, cube.measures
>>> cube.create_date_hierarchy("Date", column=table["Date"])
>>> m["Quantity.SUM"] = tt.agg.sum(table["Quantity"])
>>> m["Siblings quantity"] = tt.agg.sum(
...     m["Quantity.SUM"], scope=tt.SiblingsScope(h["Date"])
... )
>>> cube.query(
...     m["Quantity.SUM"],
...     m["Siblings quantity"],
...     levels=[l["Day"]],
...     include_totals=True,
... )
                Quantity.SUM Siblings quantity
Year  Month Day
Total                    140               140
2018                      35               140
      6                   20                35
            1             15                20
            2              5                20
      7                   15                35
            1              5                15
            2             10                15
2019                     105               140
      6                   40               105
            1             25                40
            2             15                40
      7                   65               105
            1             15                65
            2             20                65
            3             30                65
```

Using [`exclude_self`](#atoti.SiblingsScope.exclude_self):

```pycon theme={"languages":{"custom":["/engine/python-sdk/0.9/languages/pycon.tmLanguage.json"]}}
>>> m["Siblings quantity excluding self"] = tt.agg.sum(
...     m["Quantity.SUM"],
...     scope=tt.SiblingsScope(h["Date"], exclude_self=True),
... )
>>> cube.query(
...     m["Quantity.SUM"],
...     m["Siblings quantity excluding self"],
...     levels=[l["Day"]],
...     include_totals=True,
... )
                Quantity.SUM Siblings quantity excluding self
Year  Month Day
Total                    140                                0
2018                      35                              105
      6                   20                               15
            1             15                                5
            2              5                               15
      7                   15                               20
            1              5                               10
            2             10                                5
2019                     105                               35
      6                   40                               65
            1             25                               15
            2             15                               25
      7                   65                               40
            1             15                               50
            2             20                               45
            3             30                               35
```

#### exclude\_self *: [bool](https://docs.python.org/3/library/functions.html#bool)* *= False*

If `True`, the current member will not contribute to its aggregated value.

#### hierarchy *: HasIdentifier\[HierarchyIdentifier] | HierarchyIdentifier*

The hierarchy along which the aggregation will be performed.