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MousaZeidBaker / aws-lambda-typing

Python type hints for AWS Lambda
MIT License
106 stars 19 forks source link

Request for help thinking about aws_lambda_typing #63

Closed claird-ot closed 2 years ago

claird-ot commented 2 years ago

aws_lambda_typing surprises me, in that I'm accustomed to an emphasis in lambda coding on the lightest, fastest computations possible. As fond as I am of typing rigor, how can my lambda definitions afford to import aws_lambda_typing, rather than just crudely and "locally" approximating an SQSEvent as a dict, and a Context as an object?

MousaZeidBaker commented 2 years ago

Are you asking for importing only one specific object instead of importing everything? Then you can do the following 

from aws_lambda_typing.events.sqs import SQSEvent
from aws_lambda_typing.context import Context as context_
claird-ot commented 2 years ago

I appreciate you asking, MousaZeidBaker. Yes, I am fond of more precise import-ing, and practice it in my own coding; it's indeed pertinent in this conversation.

My team has a more general concern, though. Lambda-s, in our understanding, are minimal: they do the least work possible, are active as little as possible, and, in particular, put a premium on rapid coldstart time. Our current thinking is that we can only afford to import aws_lambda_typing or even from aws_lambda_typing import ... only within if TYPE_CHECKING:, because lambda-s simply can't afford the run-time cost of finding and then reading aws_lambda_typing. Has no one else raised this point?

We do not yet have satisfying ways to measure the impact of import aws_lambda_typing within a lambda. We're operating more at a folklore level, at this point.

MousaZeidBaker commented 2 years ago

aws_lambda_typing is extremely lightweight with zero dependencies (python >3.7) so I wouldn't be worried. Plus everything outside the handler method such as importing packages is only executed on cold starts.

claird-ot commented 2 years ago

Thanks, MousaZeidBaker: just the kind of detail I appreciate. While I recognize that the source is right there for inspection, and all of us can confirm those facts about light-weight actions, it might be worth summarizing them in the README.md just as you have for me: "... extremely lightweight ... only executed on cold starts." You advertise that aws_lambda_typing is "convenient"; I also needed reassurance about its safety or performance.

I'm closing this Issue now; you've answered my questions, with one exception: do you want a pull request from me, one focused exclusively on the README.md as I imagine it might be?