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Expression API

ColumnProxy

Represents a column identifier within an ActuarialFrame, acting as a starting point for expressions.

captures property

Access capture fields from a tracked rollforward.

Returns a dict-like accessor so that af.av.captures["name"] lazily extracts the Capture(name) field from the hidden rollforward Struct column.

date property

Access date-related column operations.

excel property

Access excel-related column operations.

finance property

Access finance-related column operations.

increments property

Access per-step increment fields from a tracked rollforward.

Returns a dict-like accessor so that af.av.increments["Premium"] lazily extracts the Premium increment series from the hidden rollforward Struct column.

Only meaningful when the rollforward was built with track_increments=True.

shape property

Resolved shape of this column reference (scalar, list, or unknown).

map_batches(func, return_dtype=None)

Apply a Python function to the entire column as a Series.

This is more efficient than apply for operations that can process multiple values at once, especially for NumPy or vector operations.

Parameters:

Name Type Description Default
func Callable

Function that receives a Series and returns a Series or array

required
return_dtype

Optional polars DataType for the result

None

Returns:

Name Type Description
ExpressionProxy ExpressionProxy

Result of applying the function

map_elements(func, return_dtype=None)

Apply a Python function to each element of the column.

Parameters:

Name Type Description Default
func Callable

Function to apply to each element

required
return_dtype

Optional polars DataType for the result

None

Returns:

Name Type Description
ExpressionProxy ExpressionProxy

Result of applying the function

ExpressionProxy

Represents a Polars expression derived from ActuarialFrame operations or ColumnProxy methods.

date property

Access date-related expression operations.

finance property

Access finance-related expression operations.

kind property

Resolved kind: explicit override > dtype-driven fallback > value.

shape property

Resolved shape of this expression.