> ## 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.ExternalColumn.isin()

#### ExternalColumn.isin(\*elements: Constant) → MembershipCondition\[ExternalColumnIdentifier, 'IN', Constant] | RelationalCondition\[ExternalColumnIdentifier, 'EQ', Constant]

#### ExternalColumn.isin(\*elements: Constant | [None](https://docs.python.org/3/library/constants.html#None)) → MembershipCondition\[ExternalColumnIdentifier, 'IN', Constant | [None](https://docs.python.org/3/library/constants.html#None)] | RelationalCondition\[ExternalColumnIdentifier, 'EQ', Constant | [None](https://docs.python.org/3/library/constants.html#None)]

Return a condition evaluating to `True` for elements of this column included in the given *elements*, and evaluating to `False` elsewhere.

* **Parameters:**
  **elements** – One or more values that the column elements will be compared against.