documentation: add additional information to Transformer class transform function doc string (#1243)

* doc: add additional information to Transformer class transform function doc string

Co-authored-by: Lauren Yu <[email protected]>

Author: TEChopra1000

src/sagemaker/transformer.py

@@ -68,8 +68,8 @@ def __init__(
             max_payload (int): Maximum size of the payload in a single HTTP
                 request to the container in MB.
             tags (list[dict]): List of tags for labeling a transform job
-                (default: None). For more, see
-                https://docs.aws.amazon.com/sagemaker/latest/dg/API_Tag.html.
+                (default: None). For more, see the SageMaker API documentation for
+                `Tag <https://docs.aws.amazon.com/sagemaker/latest/dg/API_Tag.html>`_.
             env (dict): Environment variables to be set for use during the
                 transform job (default: None).
             base_transform_job_name (str): Prefix for the transform job when the
@@ -146,11 +146,21 @@ def transform(
             input_filter (str): A JSONPath to select a portion of the input to
                 pass to the algorithm container for inference. If you omit the
                 field, it gets the value '$', representing the entire input.
-                For more information, see https://docs.aws.amazon.com/sagemaker/latest/dg/API_CreateTransformJob.html.
+                For CSV data, each row is taken as a JSON array,
+                so only index-based JSONPaths can be applied, e.g. $[0], $[1:].
+                CSV data should follow the `RFC format <https://tools.ietf.org/html/rfc4180>`_.
+                See `Supported JSONPath Operators
+                <https://docs.aws.amazon.com/sagemaker/latest/dg/batch-transform-data-processing.html#data-processing-operators>`_
+                for a table of supported JSONPath operators.
+                For more information, see the SageMaker API documentation for
+                `CreateTransformJob
+                <https://docs.aws.amazon.com/sagemaker/latest/dg/API_CreateTransformJob.html>`_.
                 Some examples: "$[1:]", "$.features" (default: None).
             output_filter (str): A JSONPath to select a portion of the
                 joined/original output to return as the output.
-                For more information, see https://docs.aws.amazon.com/sagemaker/latest/dg/API_CreateTransformJob.html.
+                For more information, see the SageMaker API documentation for
+                `CreateTransformJob
+                <https://docs.aws.amazon.com/sagemaker/latest/dg/API_CreateTransformJob.html>`_.
                 Some examples: "$[1:]", "$.prediction" (default: None).
             join_source (str): The source of data to be joined to the transform
                 output. It can be set to 'Input' meaning the entire input record