Using python in AWS Lambda, how do I put/get an item from a DynamoDB table?
In Node.js this would be something like:
dynamodb.getItem({
"Key": {"fruitName" : 'banana'},
"TableName": "fruitSalad"
}, function(err, data) {
if (err) {
context.fail('Incorrect username or password');
} else {
context.succeed('yay it works');
}
});
All I need is the python equivalent.
Using Boto3 (Latest AWS SDK for python)
You import it with
import boto3
Then call the client via
dynamodb = boto3.client('dynamodb')
Get item example
dynamodb.get_item(TableName='fruitSalad', Key={'fruitName':{'S':'Banana'}})
Put item example
dynamodb.put_item(TableName='fruitSalad', Item={'fruitName':{'S':'Banana'},'key2':{'N':'value2'}})
'S' indicates a String value, 'N' is a numeric value
For other data types refer http://boto3.readthedocs.org/en/latest/reference/services/dynamodb.html#DynamoDB.Client.put_item
Using latest AWS SDK
import boto3
def lambda_handler(event, context):
# this will create dynamodb resource object and
# here dynamodb is resource name
client = boto3.resource('dynamodb')
# this will search for dynamoDB table
# your table name may be different
table = client.Table("dynamoDB")
print(table.table_status)
table.put_item(Item= {'id': '34','company': 'microsoft'})
If your are using AWS you can use this code sample, only you have to give permissions to this lambda function, you can find details in link
print(table.table_status) statement returns botocore.errorfactory.ResourceNotFoundException: An error occurred (ResourceNotFoundException) when calling the DescribeTable operation: Cannot do operations on a non-existent tablefull example:
import boto3
def lambda_handler(event, context):
client = boto3.client('dynamodb')
for record in event['Records']:
# your logic here...
try:
client.update_item(TableName='dynamo_table_name', Key={'hash_key':{'N':'value'}}, AttributeUpdates={"some_key":{"Action":"PUT","Value":{"N":'value'}}})
except Exception, e:
print (e)
please note that you need to decide when to use 'update_item' or 'put_item'.
with 'update_item' you ensure to have only one record with the same hash/range. if the record exists it can update this record, else it will create it
http://boto3.readthedocs.org/en/latest/reference/services/dynamodb.html#DynamoDB.Client.update_item
You can use below lines to write and read from the DynamoDB Table:
First, import the boto3 package
import boto3
Create an object for dynamoDB
dynamodb = boto3.resource('dynamodb')
Select your specific table
table = dynamodb.Table("fruitSalad")
Write:
table.put_item(Item= {'fruitName': 'Banana'})
Read:
table.get_item(Key={'fruitName': 'Banana'})
