Amazon Simple Notification Service (SNS) has introduced an open-source Extended Client Library for Python that enables you to publish and deliver large message payloads. Previously, only the Extended Client Library for Java was available. This library is useful for messages that are larger than 256KB, up to a maximum of 2GB. The library automatically saves the actual payload to an Amazon S3 bucket and publishes the reference of the stored Amazon S3 object to the Amazon SNS topic.
Source:: Amazon AWS