Code Generation (Batch)

Code Generation (Batch)#

ibm_watsonx_data_integration.services.datastage.codegen.python_generator.PythonGenerator is an entry point that converts existing flows to Python SDK code.

For batch flows, you can use the PythonGenerator class to automatically convert assets from zip or json format to python code.

Configuration#

To use the PythonGenerator, create an instance of the generator and set the desired configuration settings.

  • mode: Generate one file per flow ('flow_per_file' by default) or combine into a single file ('single_file').

  • create_job: Add code to create a job for each flow (True by default).

  • run_job: Add code to run the auto-created jobs. Only checked if create_job is True, and defaults to True.

  • overwrite: Allow overwriting the output directory (False by default).

  • use_flow_name: Use original flow names instead of autogenerated ones (True by default).

  • api_key: Provide your API key or update the placeholder later (default is a placeholder).

  • project_id: Provide your project ID or update the placeholder later (default is a placeholder).

>>> from ibm_watsonx_data_integration import *
>>> from ibm_watsonx_data_integration.services.datastage import *
>>>
>>> # Declare a generator to use
>>> generator = PythonGenerator()
>>>
>>> # Configure settings
>>> generator.configuration.mode = 'file_per_flow'
>>> generator.configuration.create_job = True
>>> generator.configuration.run_job = True
>>> generator.configuration.api_key = 'MY_API_KEY'          # pragma: allowlist secret
>>> generator.configuration.project_id = 'MY_PROJECT_ID'

Preparing Inputs#

The input can either be a flow JSON or a zip file containing one or more flows and their dependent assets. Both of these formats can be acquired in numerous ways, but one method is to download it directly from the flow editor.

Screenshot of the flow editor for a batch flow

This is a sample project containing one batch flow and one connection used in the flow.

Screenshot of a project containing a sample batch flow and a sample connection

The flow reads data from a COS datasource, sorts it, then outputs a preview of the data.

Screenshot of the popup to download a flow and its dependencies

From this page, you can download the flow and its dependencies as a zip file.

This is the expected structure of the downloaded zip file:

downloaded_folder/
├── connections/
│   └── sample_connection.json
└── data_intg_flow/
│   └── sample_batch_flow.json
└── ...etc

Running the Generator#

Run the PythonGenerator using the PythonGenerator.generate() method

Inputs: - input_path: input_path to the JSON or zip file - output_path: (optional): the file or directory where the code will be written (if no output_path is specified, the code will not be written) Returns: - A dictionary that maps file names to the generated code strings.

>>> # Generate multiple flows from zip and write to output directory
>>> generator.generate(input_path='downloaded_folder.zip', output_path='path/to/output')
>>> # Generate one flow from JSON and write to output directory
>>> generator.generate(input_path='downloaded_folder/data_intg_flow/sample_batch_flow.json', output_path='path/to/output.py')
>>> # Generate from zip without saving files
>>> generated_code = generator.generate(input_path='downloaded_folder.zip')

Note

Zip format is preferred since it contains dependencies and therefore can be generated more completely.

Running Generated Code#

Before running the generated code, three types of placeholders may need to be replaced.

Replace the api_key and project_id placeholders if you did not set them on the generator object:

api_key = '<TODO: insert your api_key>' # pragma: allowlist secret
project = platform.projects.get(project_id='<TODO: insert your project_id>')

Sensitive or encrypted connection credentials will also be generated as placeholders:

vertica = project.create_connection(
    name='sample_vertica_conn',
    datasource_type=platform.datasources.get(name='vertica'),
    properties={
        'database': 'abcdef',
        'password': '<TODO: insert your password>',     # pragma: allowlist secret
        'username': '<TODO: insert your username>',
    },
)
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