org.apache.beam.sdk.extensions.python

Class PythonExternalTransform<InputT extends PInput,OutputT extends POutput>

java.lang.Object

org.apache.beam.sdk.transforms.PTransform<InputT,OutputT>

org.apache.beam.sdk.extensions.python.PythonExternalTransform<InputT,OutputT>

All Implemented Interfaces:

java.io.Serializable, HasDisplayData

public class PythonExternalTransform<InputT extends PInput,OutputT extends POutput>
extends PTransform<InputT,OutputT>

Wrapper for invoking external Python transforms.

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.beam.sdk.transforms.PTransform

name, resourceHints

Method Summary

Modifier and Type	Method and Description
OutputT	expand(InputT input) Override this method to specify how this PTransform should be expanded on the given InputT.
static <InputT extends PInput,OutputT extends POutput> PythonExternalTransform<InputT,OutputT>	from(java.lang.String tranformName) Instantiates a cross-language wrapper for a Python transform with a given transform name.
static <InputT extends PInput,OutputT extends POutput> PythonExternalTransform<InputT,OutputT>	from(java.lang.String tranformName, java.lang.String expansionService) Instantiates a cross-language wrapper for a Python transform with a given transform name.
PythonExternalTransform<InputT,OutputT>	withArgs(java.lang.Object... args) Positional arguments for the Python cross-language transform.
PythonExternalTransform<InputT,OutputT>	withKwarg(java.lang.String name, java.lang.Object value) Specifies a single keyword argument for the Python cross-language transform.
PythonExternalTransform<InputT,OutputT>	withKwargs(java.util.Map<java.lang.String,java.lang.Object> kwargs) Specifies keyword arguments for the Python cross-language transform.
PythonExternalTransform<InputT,OutputT>	withKwargs(Row kwargs) Specifies keyword arguments as a Row objects.

Methods inherited from class org.apache.beam.sdk.transforms.PTransform

compose, compose, getAdditionalInputs, getDefaultOutputCoder, getDefaultOutputCoder, getDefaultOutputCoder, getKindString, getName, getResourceHints, populateDisplayData, setResourceHints, toString, validate

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Detail

from

public static <InputT extends PInput,OutputT extends POutput> PythonExternalTransform<InputT,OutputT> from(java.lang.String tranformName)

Instantiates a cross-language wrapper for a Python transform with a given transform name.

Type Parameters:

InputT - Input PCollection type

OutputT - Output PCollection type

Parameters:

tranformName - fully qualified transform name.

Returns:

A PythonExternalTransform for the given transform name.

from

public static <InputT extends PInput,OutputT extends POutput> PythonExternalTransform<InputT,OutputT> from(java.lang.String tranformName,
                                                                                                           java.lang.String expansionService)

Instantiates a cross-language wrapper for a Python transform with a given transform name.

Type Parameters:

InputT - Input PCollection type

OutputT - Output PCollection type

Parameters:

tranformName - fully qualified transform name.

expansionService - address and port number for externally launched expansion service

Returns:

A PythonExternalTransform for the given transform name.

withArgs

public PythonExternalTransform<InputT,OutputT> withArgs(java.lang.Object... args)

Positional arguments for the Python cross-language transform. If invoked more than once, new arguments will be appended to the previously specified arguments.

Parameters:

args - list of arguments.

Returns:

updated wrapper for the cross-language transform.

withKwarg

public PythonExternalTransform<InputT,OutputT> withKwarg(java.lang.String name,
                                                         java.lang.Object value)

Specifies a single keyword argument for the Python cross-language transform. This may be invoked multiple times to add more than one keyword argument.

Parameters:

name - argument name.

value - argument value

Returns:

updated wrapper for the cross-language transform.

withKwargs

public PythonExternalTransform<InputT,OutputT> withKwargs(java.util.Map<java.lang.String,java.lang.Object> kwargs)

Specifies keyword arguments for the Python cross-language transform. If invoked more than once, new keyword arguments map will be added to the previously prided keyword arguments.

Returns:

updated wrapper for the cross-language transform.

withKwargs

public PythonExternalTransform<InputT,OutputT> withKwargs(Row kwargs)

Specifies keyword arguments as a Row objects.

Parameters:

kwargs - keyword arguments as a Row objects. An empty Row represents zero keyword arguments.

Returns:

updated wrapper for the cross-language transform.

expand

public OutputT expand(InputT input)

Description copied from class: PTransform

Override this method to specify how this PTransform should be expanded on the given InputT.

NOTE: This method should not be called directly. Instead apply the PTransform should be applied to the InputT using the apply method.

Composite transforms, which are defined in terms of other transforms, should return the output of one of the composed transforms. Non-composite transforms, which do not apply any transforms internally, should return a new unbound output and register evaluators (via backend-specific registration methods).

Specified by:

expand in class PTransform<InputT extends PInput,OutputT extends POutput>