[aws-stepfunctions] Support for ResultSelector

[rodrick10]

I have trying to find a way of using the ResultSelector with the stef functions python sdk just like with have input_path, result_path or output_path. Seems like there is not a method to implemnet this feature.

There is a similar issue but for the cdk project: cdk_issue

In my case I want to select the output of a LambdaStep to only consider the Payload. Something like this:

lambda_step= steps.compute.LambdaStep(
    "Lambda ID",
    parameters={"FunctionName": "function_name"}
    result_selector: {"output.$": "$.output.Payload"}
   )

This is a 🚀 Feature Request

[wong-a]

Thanks for the feature request. This is a missing capability in the Python SDK. Closing as a duplicate of #95

There is an open PR to add it (#102). I'll follow up with the team to see how we can get this shipped.