Python¶

This plugin allows execution of Python code on streamed data using the GraalVM Python engine.

Features¶

Execute Python code on input data
Load Python code from a file or provide it inline
Set a timeout for Python execution
Access input data from Python
Emit output data from Python

The Python processor can also be configured to limit script execution time.

Python API¶

The JavaScript code can access the input data passed to the processor.

The Python code should define a process function that takes the input data and returns the output data:

def process(input):
  # Process the input data
  return output

Security Considerations¶

The Python processor runs with limited permissions by default. It cannot access the file system, network, or other system resources unless explicitly allowed.

JAVAYAML

.processWith(PythonConfigBuilder.builder()
    .withScript(value)
    .withScriptUrl(value)
    .withTimeout(value)
)

processor:
  python:
    script: value
    scriptUrl: value
    timeout: value

Java dependency management¶

Add this declaration to your dependency management system to access the configuration DSL for this plugin in Java.

MavenGradle

<dependency>
    <groupId>org.voltdb</groupId>
    <artifactId>volt-stream-plugin-python-api</artifactId>
    <version>1.0-20250910-124207-release-1.5.3</version>
</dependency>

implementation group: 'org.voltdb', name: 'volt-stream-plugin-python-api', version: '1.0-20250910-124207-release-1.5.3'

Properties¶

`script`¶

Python code to execute Type: string

`scriptUrl`¶

URL to a Python file to execute Type: string

`timeout`¶

Maximum execution time in milliseconds Type: object

Default value: 1s

Usage Examples¶

YAML

Capitalise all strings.

version: 1
name: PythonProcessorExample

source:
  file:
    path: "input.txt"

pipeline:
  processors:
    - python:
        name: "python-processor"
        script: |
          def process(input):
            if isinstance(input, str):
              return input.upper()
            return input

sink:
  stdout: {}