Dynamodb scan "Float types are not supported. Use Decimal types instead" when filtering on decimal

I’m stumped on this one..

this is my scan:

        response = table.scan(
        FilterExpression=Attr('ttl').gte(Decimal(time.time()-900)) & Attr('SessionStatus').eq('failed'))

Yet when I run it, I get error: Float types are not supported. Use Decimal types instead.

What am I doing wrong?

>Solution :

In DynamoDB, float types are not directly supported, and it’s recommended to use Decimal types instead to maintain precision when working with decimal numbers. Try the code below instead

import boto3
import time
from boto3.dynamodb.conditions import Attr
from decimal import Decimal

# Initialize DynamoDB client
dynamodb_client = boto3.client('dynamodb', region_name='YOUR_REGION')

# Function to perform the scan
def scan_with_filter():
    try:
        # Calculate the time threshold for 15 minutes ago
        time_threshold = Decimal(str(time.time() - 900))  # 900 seconds = 15 minutes

        # Define scan parameters with the updated FilterExpression
        scan_params = {
            'TableName': 'YOUR_TABLE_NAME',
            'FilterExpression': Attr('ttl').gte(time_threshold) & Attr('SessionStatus').eq('failed')
        }

        response = dynamodb_client.scan(**scan_params)

        # Process scanned items
        items = response.get('Items', [])
        print("Scanned items:", items)
    except Exception as e:
        print("Error scanning DynamoDB table:", e)

# Perform the scan with the specified FilterExpression
scan_with_filter()