Typing

This typing utility provides static typing classes that can be used to ease the development by providing the IDE type hints.

Key features

• Add static typing classes
• Ease the development by leveraging your IDE's type hints
• Avoid common typing mistakes in Python

Getting started

Tip

All examples shared in this documentation are available within the project repository.

We provide static typing for any context methods or properties implemented by Lambda context object.

LambdaContext

The LambdaContext typing is typically used in the handler method for the Lambda function.

getting_started_validator_decorator_function.py

from aws_lambda_powertools.utilities.typing import LambdaContext


def handler(event: dict, context: LambdaContext) -> dict:
    # Insert business logic
    return event

Working with context methods and properties

Using LambdaContext typing makes it possible to access information and hints of all properties and methods implemented by Lambda context object.

working_with_context_function.py

from time import sleep

import requests

from aws_lambda_powertools import Logger
from aws_lambda_powertools.utilities.typing import LambdaContext

logger = Logger()


def lambda_handler(event, context: LambdaContext) -> dict:

    limit_execution: int = 1000  # milliseconds

    # scrape website and exit before lambda timeout
    while context.get_remaining_time_in_millis() > limit_execution:

        comments: requests.Response = requests.get("https://jsonplaceholder.typicode.com/comments")
        # add logic here and save the results of the request to an S3 bucket, for example.

        logger.info(
            {
                "operation": "scrape_website",
                "request_id": context.aws_request_id,
                "remaining_time": context.get_remaining_time_in_millis(),
                "comments": comments.json()[:2],
            }
        )

        sleep(1)

    return {"message": "Success"}

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Last update: 2022-08-25