etl_lib.data_sink.CSVBatchSink module

class CSVBatchSink(context, task, predecessor, file_path, **kwargs)

Bases: BatchProcessor

BatchProcessor to write batches of data to a CSV file.

Parameters:

• context (ETLContext)

• task (Task)

• predecessor (BatchProcessor)

• file_path (Path)

__init__(context, task, predecessor, file_path, **kwargs)

Constructs a new CSVBatchSink.

Parameters:

• context (ETLContext) – etl_lib.core.ETLContext.ETLContext instance.

• task (Task) – etl_lib.core.Task.Task instance owning this batchProcessor.

• predecessor (BatchProcessor) – BatchProcessor which get_batch() function will be called to receive batches to process.

• file_path (Path) – Path to the CSV file where data will be written. If the file exists, data will be appended.

• **kwargs – Additional arguments passed to csv.DictWriter to allow tuning the csv creation.

get_batch(batch_size)

Provides a batch of data to the caller.

The batch itself could be called and processed from the provided predecessor or generated from other sources.

Parameters:

• max_batch__size – The max size of the batch the caller expects to receive.

• batch_size (int)

Return type:

Generator[BatchResults, None, None]

Returns

A generator that yields batches.