deephaven.updateby¶

This module supports building various operations for use with the update-by Table operation.

class BadDataBehavior(value)[source]¶

Bases: Enum

An Enum defining ways to handle invalid data during update-by operations.

POISON = io.deephaven.api.updateby.BadDataBehavior(objectRef=0x5607dfd132c8)¶: Allow the bad data to poison the result. This is only valid for use with NaN

RESET = io.deephaven.api.updateby.BadDataBehavior(objectRef=0x5607dfd132b8)¶: Reset the state for the bucket to None when invalid data is encountered

SKIP = io.deephaven.api.updateby.BadDataBehavior(objectRef=0x5607dfd132c0)¶: Skip and do not process the invalid data without changing state

THROW = io.deephaven.api.updateby.BadDataBehavior(objectRef=0x5607dfd132b0)¶: Throw an exception and abort processing when bad data is encountered

class DeltaControl(value)[source]¶

Bases: Enum

An Enum defining ways to handle null values during update-by Delta operations where delta operations return the difference between the current row and the previous row.

NULL_DOMINATES = io.deephaven.api.updateby.DeltaControl(objectRef=0x5607dfd20640)¶: A valid value following a null value returns null

VALUE_DOMINATES = io.deephaven.api.updateby.DeltaControl(objectRef=0x5607dfd20648)¶: A valid value following a null value returns the valid value

ZERO_DOMINATES = io.deephaven.api.updateby.DeltaControl(objectRef=0x5607dfd20650)¶: A valid value following a null value returns zero

class MathContext(value)[source]¶

Bases: Enum

An Enum for predefined precision and rounding settings in numeric calculation.

DECIMAL128 = java.math.MathContext(objectRef=0x5607dfd20678)¶: a precision setting matching the IEEE 754R Decimal128 format, 34 digits, rounding is half-even

DECIMAL32 = java.math.MathContext(objectRef=0x5607dfd20668)¶: a precision setting matching the IEEE 754R Decimal32 format, 7 digits, rounding is half-even

DECIMAL64 = java.math.MathContext(objectRef=0x5607dfd20670)¶: a precision setting matching the IEEE 754R Decimal64 format, 16 digits, rounding is half-even

UNLIMITED = java.math.MathContext(objectRef=0x5607dfd20660)¶: unlimited precision arithmetic, rounding is half-up

class OperationControl(on_null=BadDataBehavior.SKIP, on_nan=BadDataBehavior.SKIP, big_value_context=MathContext.DECIMAL128)[source]¶

Bases: JObjectWrapper

A OperationControl represents control parameters for performing operations with the table UpdateByOperation.

j_object_type¶: alias of OperationControl

class UpdateByOperation(j_updateby_op)[source]¶

Bases: JObjectWrapper

A UpdateByOperation represents an operator for the Table update-by operation.

j_object_type¶: alias of UpdateByOperation

cum_max(cols)[source]¶

Creates a cumulative maximum UpdateByOperation for the supplied column names.

Parameters:: cols (Union[str, List[str]]) – the column(s) to be operated on, can include expressions to rename the output, i.e. “new_col = col”; when empty, update_by performs the cumulative maximum operation on all the applicable columns.
Return type:: UpdateByOperation
Returns:: an UpdateByOperation
Raises:: DHError –

cum_min(cols)[source]¶

Creates a cumulative minimum UpdateByOperation for the supplied column names.

Parameters:: cols (Union[str, List[str]]) – the column(s) to be operated on, can include expressions to rename the output, i.e. “new_col = col”; when empty, update_by performs the cumulative minimum operation on all the applicable columns.
Return type:: UpdateByOperation
Returns:: an UpdateByOperation
Raises:: DHError –

cum_prod(cols)[source]¶

Creates a cumulative product UpdateByOperation for the supplied column names.

Parameters:: cols (Union[str, List[str]]) – the column(s) to be operated on, can include expressions to rename the output, i.e. “new_col = col”; when empty, update_by performing the cumulative product operation on all the applicable columns.
Return type:: UpdateByOperation
Returns:: an UpdateByOperation
Raises:: DHError –

cum_sum(cols)[source]¶

Creates a cumulative sum UpdateByOperation for the supplied column names.

Parameters:: cols (Union[str, List[str]]) – the column(s) to be operated on, can include expressions to rename the output, i.e. “new_col = col”; when empty, update_by performs the cumulative sum operation on all the applicable columns.
Return type:: UpdateByOperation
Returns:: an UpdateByOperation
Raises:: DHError –

delta(cols, delta_control=DeltaControl.NULL_DOMINATES)[source]¶

Creates a delta UpdateByOperation for the supplied column names. The Delta operation produces values by computing the difference between the current value and the previous value. When the current value is null, this operation will output null. When the current value is valid, the output will depend on the DeltaControl provided.

When delta_control is not provided or set to NULL_DOMINATES, a value following a null value returns null. When delta_control is set to VALUE_DOMINATES, a value following a null value returns the value. When delta_control is set to ZERO_DOMINATES, a value following a null value returns zero.

Parameters:

cols (Union[str, List[str]]) – the column(s) to be operated on, can include expressions to rename the output, i.e. “new_col = col”; when empty, update_by performs the delta operation on all the applicable columns.
delta_control (DeltaControl) – defines how special cases should behave; when None, the default DeltaControl settings of VALUE_DOMINATES will be used

Return type: