Assuming you are using a proxy integration the event looks like this: https://docs.aws.amazon.com/lambda/latest/dg/services-apigateway.html#apigateway-example-event The context object: https://docs.aws.amazon.com/lambda/latest/dg/python-context.html Answer from chrisdubya555 on reddit.com
Amazon Web Services
docs.aws.amazon.com › aws lambda › developer guide › building lambda functions with python › define lambda function handler in python
Define Lambda function handler in Python - AWS Lambda
January 31, 2026 - The most common way to declare a handler function in Python is as follows: ... from typing import Dict, Any def lambda_handler(event: Dict[str, Any], context: Any) -> Dict[str, Any]: To use specific AWS typing for events generated by other AWS services and for the context object, add the aws-lambda-typing package to your function's deployment package.
Readthedocs
aws-lambda-for-python-developers.readthedocs.io › en › latest › 02_event_and_context
Chapter 2: What is the event & context? - AWS Lambda for Python Developers
As we dive deeper into AWS Lambda, we'll find more and more possible events that can trigger lambdas, such as: ... Each event will have a different format and carry different payloads, but the pattern is always the same. The lambda function is triggered, it will inspect its event and perform a logic on the event before returning and terminating. Now that we've covered event, let's move onto context. context is a Python ...
What fields/properties do 'event' and 'context' have in a Python Lambda invoked by API Gateway?
Assuming you are using a proxy integration the event looks like this: https://docs.aws.amazon.com/lambda/latest/dg/services-apigateway.html#apigateway-example-event The context object: https://docs.aws.amazon.com/lambda/latest/dg/python-context.html More on reddit.com
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3
September 23, 2022python - Lambda calling Lambda - how to access the payload in the second? - Stack Overflow
Note, you may want to take a look ... for Lambda B to complete. ... Find the answer to your question by asking. Ask question ... See similar questions with these tags. ... This question is in a collective: a subcommunity defined by tags with relevant content and experts. ... 5 How to pass Python objects (that are not JSON serializable) from one (AWS) lambda function ... More on stackoverflow.com
amazon web services - How to access the event object with python in AWS Lambda? - Stack Overflow
To follow up on this question: Filter CloudWatch Logs to extract Instance ID I think it leaves the question incomplete because it does not say how to access the event object with python. My goal ... More on stackoverflow.com
aws lambda + http api with Payload Format Version 2.0. How to correctly parse the payload with Python 3.12 runtime
I am developing a lambda (runtime Python 3.12) that will process events via POST requests to a API Gateway HTTP API. According to the AWS console, the integration I have set up between the POST route on my API and my lambda function has "Payload format version 2.0 (interpreted response format). More on repost.aws
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July 8, 2024Videos
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AWS Lambda For Absolute Beginners: Python Tutorial in 25 Minutes ...
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AWS S3 File Upload + Lambda Trigger (Tutorial In Python) - Step ...
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AWS with Python: Mastering Lambda Basics - YouTube
09:09
AWS # 066 # Lambda - Event & Context Object - YouTube
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AWS with Python: Invoking Lambda Functions using Boto3 - YouTube
13:54
Simplified step-by-step process for beginners to understand how ...
Amazon Web Services
docs.aws.amazon.com › aws lambda › developer guide › building lambda functions with python › using the lambda context object to retrieve python function information
Using the Lambda context object to retrieve Python function information - AWS Lambda
in the powertools-lambda-python repository on GitHub. The following example shows a handler function that logs context information. import time def lambda_handler(event, context): print("Lambda function ARN:", context.invoked_function_arn) print("CloudWatch log stream name:", context.log_stream_name) print("CloudWatch log group name:", context.log_group_name) print("Lambda Request ID:", context.aws_request_id) print("Lambda function memory limits in MB:", context.memory_limit_in_mb) # We have added a 1 second delay so you can see the time remaining in get_remaining_time_in_millis.
AWS
docs.aws.amazon.com › powertools › python › 3.10.0 › utilities › data_classes
Event Source Data Classes - Powertools for AWS Lambda (Python)
When an event matching a defined rule occurs in EventBridge, it can automatically trigger a Lambda function, passing the event data as input. ... This example is based on the AWS docs for Amazon MSK and self-managed Apache Kafka. ... Kinesis events by default contain base64 encoded data. You can use the helper function to access the data either as json or plain text, depending on the original payload.
Amazon Web Services
docs.aws.amazon.com › aws lambda › developer guide › code examples for lambda using aws sdks › serverless examples for lambda › invoke a lambda function from an amazon sns trigger
Invoke a Lambda function from an Amazon SNS trigger - AWS Lambda
July 31, 2023 - Consuming an SNS event with Lambda using Python.
AWS
docs.aws.amazon.com › cdk › api › v2 › python › aws_cdk.aws_lambda_event_sources › README.html
AWS Lambda Event Sources — AWS Cloud Development Kit 2.238.0 documentation
You can use the bucket notification configuration feature in Amazon S3 to configure the event source mapping, identifying the bucket events that you want Amazon S3 to publish and which Lambda function to invoke. import aws_cdk.aws_s3 as s3 from aws_cdk.aws_lambda_event_sources import S3EventSource # fn: lambda.Function bucket = s3.Bucket(self, "mybucket") fn.add_event_source(S3EventSource(bucket, events=[s3.EventType.OBJECT_CREATED, s3.EventType.OBJECT_REMOVED], filters=[s3.NotificationKeyFilter(prefix="subdir/")] ))
Reddit
reddit.com › r/aws › what fields/properties do 'event' and 'context' have in a python lambda invoked by api gateway?
r/aws on Reddit: What fields/properties do 'event' and 'context' have in a Python Lambda invoked by API Gateway?
September 23, 2022 -
I am writing a Python Lambda that will be invoked via HTTP. A web service will make an HTTP call to an API Gateway resource that I define, which will then invoke the Lambda. My Lambda handler will look like:
def lambda_handler(event, context):
// do stuff down here
return responseObjectI am trying to find documentation on event and context so I know how to do things like:
-
extract query string parameters from requests
-
extract path parameters from requests
-
inspect the request entity
-
etc.
Surprising I can find no official AWS documentation on what fields/properties these two objects have on them when they are invoked from an API Gateway resource action. I found this article which was sort of helpful but nothing official from AWS. Can anyone point me in the right direction?
Top answer 1 of 2
5
Assuming you are using a proxy integration the event looks like this: https://docs.aws.amazon.com/lambda/latest/dg/services-apigateway.html#apigateway-example-event The context object: https://docs.aws.amazon.com/lambda/latest/dg/python-context.html
2 of 2
2
Easy, just do a print(event) and put the result in a JSON formatter for easy viewing :)
Stack Overflow
stackoverflow.com › questions › 55422499 › lambda-calling-lambda-how-to-access-the-payload-in-the-second
python - Lambda calling Lambda - how to access the payload in the second? - Stack Overflow
It would benefit any readers if you clarified the differences between reading from event and reading from context, and in what situations they should be accessed. 2021-03-15T03:29:37.147Z+00:00 ... I got this error message "errorMessage": "'LambdaContext' object is not subscriptable" if I used context to retrieve payload. 2023-01-31T12:06:42.957Z+00:00 ... Possible duplicate question -- Nodejs - Invoke an AWS.Lambda function from within another lambda function
Top answer 1 of 4
1
The event data passed to Lambda contains the Instance ID.
You then need to call describe_tags() to retrieve a dictionary of the tags.
import boto3
client = boto3.client('ec2')
client.describe_tags(Filters=[
{
'Name': 'resource-id',
'Values': [
event['detail']['instance-id']
]
}
]
)
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0
In the Details Section of the Event, you will get the instance Id's. Using the instance id and AWS SDK you can query the tags. The following is the sample event
{
"version": "0",
"id": "ee376907-2647-4179-9203-343cfb3017a4",
"detail-type": "EC2 Instance State-change Notification",
"source": "aws.ec2",
"account": "123456789012",
"time": "2015-11-11T21:30:34Z",
"region": "us-east-1",
"resources": [
"arn:aws:ec2:us-east-1:123456789012:instance/i-abcd1111"
],
"detail": {
"instance-id": "i-abcd1111",
"state": "running"
}
}
PyPI
pypi.org › project › aws-lambda-event-handler
aws-lambda-event-handler · PyPI
This package provides a decorator for Python Lambda functions handling AWS Lambda Event Records. ... This package provides a decorator for Python Lambda functions handling individual records in the event payload of the AWS Lambda function.
» pip install aws-lambda-event-handler
GitHub
gist.github.com › pgolding › 4edc4f3d066679117bba187105678028
Passing AWS Lambda Function parameters using the ClientContext object in Python · GitHub
event = {"body": { "my": "data" }} # body not necessary, but compatible with API gateway invocation res = lambda_client.invoke(FunctionName='<your_function_name>', InvocationType='RequestResponse', ClientContext=base64.b64encode(b'{"custom":{"foo":"bar", \ "fuzzy":"wuzzy"}}').decode('utf-8'), Payload=json.dumps(event)) It can then be access in the lambda function like so: def my_handler(event,context): my_custom_dict = context.client_context.custom foo = my_custom_dict["foo"] # "bar" # and so on · The use of the custom field is kind of mentioned here, but not very well: http://docs.aws.amazon.com/lambda/latest/dg/python-context-object.html ·
Amazon Web Services
docs.aws.amazon.com › lambda › latest › dg › services-apigateway-code.html
Sample function code - AWS Lambda
March 21, 2022 - from __future__ import print_function import boto3 import json print('Loading function') def handler(event, context): '''Provide an event that contains the following keys: - operation: one of the operations in the operations dict below - tableName: required for operations that interact with DynamoDB - payload: a parameter to pass to the operation being performed ''' #print("Received event: " + json.dumps(event, indent=2)) operation = event['operation'] if 'tableName' in event: dynamo = boto3.resource('dynamodb').Table(event['tableName']) operations = { 'create': lambda x: dynamo.put_item(**x),
AWS re:Post
repost.aws › questions › QUKgLjyLh8Rb2uQDWk3WMzcA › error-trying-to-parse-event-from-api-http-integration-in-lambda-python-3-12-runtime
error trying to parse event from API HTTP integration in lambda Python 3.12 runtime | AWS re:Post
July 8, 2024 - { "errorMessage": "the JSON object must be str, bytes or bytearray, not dict", "errorType": "TypeError", "requestId": "47eb32f4-97a9-44de-a144-bc19b5d7e959", "stackTrace": [ " File \"/var/task/lambda_function.py\", line 33, in handler\n payload = json.loads(event)\n", " File \"/var/lang/lib/python3.12/json/__init__.py\", line 339, in loads\n raise TypeError(f'the JSON object must be str, bytes or bytearray, '\n" ] }
CloudThat
cloudthat.com › home › blogs › understanding aws lambda event sources in python
Understanding AWS Lambda Event Sources in Python
February 9, 2026 - The aws_cdk.aws_lambda_event_sources module provides classes that represent different AWS services as event sources for AWS Lambda. This means you can use Python code to tell AWS Lambda where to listen for events.
Pydantic
pydantic.dev › articles › lambda-intro
AWS Lambda: Validate event & context data via Pydantic
April 4, 2024 - It also assumes that you've configured your Lambda function with the name my-function. The --payload option is used to pass the event data to the Lambda function, and the output of the ...
Medium
medium.com › cyberark-engineering › aws-lambda-event-validation-in-python-now-with-powertools-431852ac7caa
AWS Lambda Event Validation in Python — Now with PowerTools | by Ran Isenberg | CyberArk Engineering | Medium
April 23, 2022 - You will offload the maintenance of Pydantic based AWS events schemas from your code to AWS. You will be introduced to one of the best new AWS Lambda related libraries which might solve you other issues you didn't even know you had. Recently, I had the pleasure of contributing a new parser utility code to an amazing and relatively new project on Github: AWS Lambda Powertools. This repo, which started as Python oriented (but now supports other languages such as Java and more to follow) provides an easy to use solution for lambda logging, tracing (with cloud watch metrics), SSM utilities and now validation and advanced parsing for incoming AWS Lambda events.
Learning-Ocean
learning-ocean.com › tutorials › aws › mastering-aws-lambda-event-objects
Aws - AWS Lambda: Event Objects - Learning-Ocean
S3 Event Processing: Convert uploaded videos to multiple formats for streaming purposes. Scheduling Tasks: Automatically start and stop EC2 instances at specific times to save costs. Dynamic Responses: Process user inputs and return customized results directly via the Function URL. # List all EC2 instances and stop those with low utilization import boto3 def lambda_handler(event, context): ec2 = boto3.client('ec2') instances = ec2.describe_instances(Filters=[{"Name": "instance-state-name", "Values": ["running"]}]) for reservation in instances['Reservations']: for instance in reservation['Instances']: # Add logic to check utilization metrics and stop instances pass
Top answer 1 of 2
2
You are having this problem because the contents of the body is a JSON. But in string format. You should parse it to be able to access it like a normal dictionary. Like so:
import json
def handler(event: dict, context: object):
body = event['Records'][0]['body']
body = json.loads(body)
# use the body as a normal dictionary
You are getting only a single char when using integer indexes because it is a string. So, using [n] in an string will return the nth char.
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2
It's because your getting stringified JSON data. You need to load it back to its Python dict format.
There is a useful package called lambda_decorators. you can install with pip install lambda_decorators
so you can do this:
from lambda_decorators import load_json_body
@load_json_body
def lambda_handler(event, context):
print(event['Records'][0]['body'])
# Now you can access the the items in the body using there index and keys.
This will extract the JSON for you.