> ## 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.Measure

### *final class* atoti.Measure

A measure is a mostly-numeric data value, computed on demand for aggregation purposes.

### Example

Copying a measure does not copy its attributes:

```pycon theme={"languages":{"custom":["/engine/python-sdk/0.9/languages/pycon.tmLanguage.json"]}}
>>> table = session.create_table("Example", data_types={"ID": "String"})
>>> cube = session.create_cube(table)
>>> m = cube.measures
>>> m["Original"] = 1
>>> m["Original"].description = "Test description"
>>> m["Original"].folder = "Test folder"
>>> m["Original"].formatter = "INT[test: #,###]"
>>> m["Original"].visible = False
>>> m["Copy"] = m["Original"]
>>> m["Copy"].description
''
>>> print(m["Copy"].folder)
None
>>> m["Copy"].formatter
'INT[#,###]'
>>> m["Copy"].visible
True
```

Redefining a measure resets its attributes:

```pycon theme={"languages":{"custom":["/engine/python-sdk/0.9/languages/pycon.tmLanguage.json"]}}
>>> m["Original"] = 2
>>> m["Original"].description
''
>>> print(m["Original"].folder)
None
>>> m["Original"].formatter
'INT[#,###]'
>>> m["Original"].visible
True
```

<Callout icon="link">
  **See also**:
  [`Measures`](./atoti.measures#atoti.measures.Measures) to define one.
</Callout>

| [`data_type`](./atoti.Measure.data_type#atoti.Measure.data_type)       | Type of the values the measure evaluates to.                                                                                            |
| ---------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------- |
| [`description`](./atoti.Measure.description#atoti.Measure.description) | Description of the measure.                                                                                                             |
| [`folder`](./atoti.Measure.folder#atoti.Measure.folder)                | Folder of the measure.                                                                                                                  |
| [`formatter`](./atoti.Measure.formatter#atoti.Measure.formatter)       | Formatter of the measure.                                                                                                               |
| [`isin`](./atoti.Measure.isin#atoti.Measure.isin)                      | Return a condition evaluating to `True` where this measure evaluates to one of the given *values*, and evaluating to `False` elsewhere. |
| [`isnull`](./atoti.Measure.isnull#atoti.Measure.isnull)                | Return a condition evaluating to `True` where this measure evalutes to `None`, and evaluating to `False` elsewhere.                     |
| [`name`](./atoti.Measure.name#atoti.Measure.name)                      | Name of the measure.                                                                                                                    |
| [`visible`](./atoti.Measure.visible#atoti.Measure.visible)             | Whether the measure is visible or not.                                                                                                  |