# Warnings

class `agate.``NullCalculationWarning`

  Bases: `RuntimeWarning`

  Warning raised if a calculation which can not logically account for null values is performed on a `Column` containing nulls.

class `agate.``DuplicateColumnWarning`

  Bases: `RuntimeWarning`

  Warning raised if multiple columns with the same name are added to a new `Table`.

`agate.``warn_null_calculation`(operation, column)

`agate.``warn_duplicate_column`(column_name, column_rename)