DynamoDB

Local Development

# Source: https://dynobase.dev/run-dynamodb-locally/
# Create a file called docker-compose.yml and paste following code:
# docker-compose.yml
version: "3.5"

services:
  dynamo:
    container_name: local-dynamodb
    image: amazon/dynamodb-local
    networks:
      - local-dynamodb
    ports:
      - "8000:8000"
    volumes:
      - dynamodata:/home/dynamodblocal
    working_dir: /home/dynamodblocal
    command: "-jar DynamoDBLocal.jar -sharedDb -dbPath ."

networks:
  local-dynamodb:
    name: local-dynamodb

volumes:
  dynamodata: {}

# Run docker-compose up -d. You can skip -d flag if you don't want to run in in the "detached" mode.
docker-compose up -d

// Deserialize dynamodb obj -> python and python dict --> dynamodb obj
// source: https://towardsaws.com/making-use-of-boto3-out-of-the-box-dynamodb-serializers-1dffbc7deafe
from boto3.dynamodb.types import TypeDeserializer, TypeSerializer
def dynamo_obj_to_python_obj(dynamo_obj: dict) -> dict:
    deserializer = TypeDeserializer()
    return {
        k: deserializer.deserialize(v) 
        for k, v in dynamo_obj.items()
    }  
  
def python_obj_to_dynamo_obj(python_obj: dict) -> dict:
    serializer = TypeSerializer()
    return {
        k: serializer.serialize(v)
        for k, v in python_obj.items()
    }

Useful links

• https://www.tecracer.com/blog/2021/04/working-with-lists-in-dynamodb.html