將 DiscoverInputSchema 與 AWS SDK 搭配使用

class KinesisAnalyticsApplicationV2:
    """Encapsulates Kinesis Data Analytics application functions."""

    def __init__(self, analytics_client):
        """
        :param analytics_client: A Boto3 Kinesis Data Analytics v2 client.
        """
        self.analytics_client = analytics_client
        self.name = None
        self.arn = None
        self.version_id = None
        self.create_timestamp = None


    def discover_input_schema(self, stream_arn, role_arn):
        """
        Discovers a schema that maps data in a stream to a format that is usable by
        an application's runtime environment. The stream must be active and have
        enough data moving through it for the service to sample. The returned schema
        can be used when you add the stream as an input to the application or you can
        write your own schema.

        :param stream_arn: The ARN of the stream to map.
        :param role_arn: A role that lets Kinesis Data Analytics read from the stream.
        :return: The discovered schema of the data in the input stream.
        """
        try:
            response = self.analytics_client.discover_input_schema(
                ResourceARN=stream_arn,
                ServiceExecutionRole=role_arn,
                InputStartingPositionConfiguration={"InputStartingPosition": "NOW"},
            )
            schema = response["InputSchema"]
            logger.info("Discovered input schema for stream %s.", stream_arn)
        except ClientError:
            logger.exception(
                "Couldn't discover input schema for stream %s.", stream_arn
            )
            raise
        else:
            return schema