How do I conditionally insert an item into a dynamodb table using boto3

Question

If I have a table with a hash key of userId and a range key of productId how do I put an item into that table only if it doesn\'t already exist using boto3\'s dynamodb bindi

Answer 1

You dont need the sortkey( or range key) just the partition key or hash key is enough.

try:
    table.put_item(
        Item={
            'foo':1,
            'bar':2,
        },
        ConditionExpression='attribute_not_exists(foo)'
    )
except botocore.exceptions.ClientError as e:
    # Ignore the ConditionalCheckFailedException, bubble up
    # other exceptions.
    if e.response['Error']['Code'] != 'ConditionalCheckFailedException':
        raise