Processor

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id: py-Processor

Processor

The Processor class provides access to the current processor's configuration and runtime properties. It is available globally as processor in every Python processor.

Use it to retrieve configured arguments, resolve output ports, expand environment macros, and log processor-specific messages.

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At a Glance

# Get configured arguments from the UI
args = processor.arguments
timeout = args.get('timeout', 5000)

# Resolve an output port for emitting messages
OUTPUT_PORT = processor.getOutputPort('Output')

# Expand environment variables in strings
db_host = processor.expandString('${lay:DB_HOST}')

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Properties

Property	Type	Description
arguments	dict	JSON arguments configured in the Python Asset editor
name	str	The name of the current processor

arguments

Arguments entered via the Python Asset editor in the UI. Returned as a Python dictionary.

args = processor.arguments

# Access individual properties
max_retries = args.get('maxRetries', 3)
api_endpoint = args.get('apiEndpoint')

stream.logInfo(f'Configured retries: {max_retries}')

name

The processor name as defined in the workflow diagram.

processor_name = processor.name  # e.g., "Validate-Order"

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Methods

getArguments()

Returns the configured arguments. Same as arguments.

Returns: dict

args = processor.getArguments()

getName()

Returns the processor name. Same as name.

Returns: str

name = processor.getName()

getOutputPort(portName)

Returns an OutputPort instance for the given port name. Use this to obtain the port reference needed by stream.emit().

Parameter	Type	Description
portName	str	The name of the output port as defined in the workflow

Returns: OutputPort

# In on_init — resolve ports once
OUTPUT_PORT = None
ERROR_PORT = None

def on_init():
    global OUTPUT_PORT, ERROR_PORT
    OUTPUT_PORT = processor.getOutputPort('Output')
    ERROR_PORT = processor.getOutputPort('Error')

def on_message():
    if is_valid(message):
        stream.emit(message, OUTPUT_PORT)
    else:
        stream.emit(message, ERROR_PORT)

expandString(toExpand)

Expands macros within a string using environment variables, secrets, and other configured values.

Parameter	Type	Description
toExpand	str	String containing ${lay:VARNAME} style macros

Returns: str — The expanded string

# Expand environment variables
db_url = processor.expandString('jdbc:postgresql://${lay:DB_HOST}:${lay:DB_PORT}/mydb')
# Result: "jdbc:postgresql://db-server.internal:5432/mydb"

# Expand with defaults
timeout = processor.expandString('${lay:TIMEOUT:-30000}')

Macro Documentation

See the macro documentation for all available macro types and syntax.

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Logging

Log messages at different severity levels. These appear in the Audit Trail and processor terminal output.

Method	Severity	Use For
logInfo(param)	INFO	General information, progress updates
logWarning(param)	WARNING	Non-critical issues that need attention
logError(param)	ERROR	Errors that affect processing
logFatal(param)	FATAL	Critical failures requiring immediate action

Each method accepts either a str or a Status object.

# Log a simple message
processor.logInfo(f'Processing order {order_id}')

# Log a warning with context
processor.logWarning(f'Unexpected value: {value}')

# Log an error as a Status object
err_status = Status.create(VENDOR, 'VALIDATION_FAILED', field_name)
processor.logError(err_status)

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See Also

• OutputPort — The ports you obtain and emit to
• PythonProcessor — Lifecycle hooks (on_init, on_message, etc.)
• Macro documentation — Full macro syntax reference