Is it good practice to add optional arguments to AWS lambda function?

Question

For example, a python AWS lambda, the documented signature is:

def handler(event, context):

But the following is valid python syntax:

def handler(event, context, *args, **kwargs):

I've tested this and the lambda does not crashes. (BTW default arguments is also valid)

This would allow, for example, to decorate the handler function and then introduce extra arguments to the function. Think about a dependency injection scenario for example.

Is 'altering' the default signature considered bad practice in any way, and if so, in which way?

When the AWS Lambda service calls the function, it will only pass `event` and `context`. What are you wanting to achieve by adding arguments? — John Rotenstein, May 18 '23 at 06:01
To decorate the function so I can add things there. I'm not expecting that AWS service adds anything, it wouldn't. — Javier Novoa C., May 18 '23 at 06:02

score 1 · Accepted Answer · answered May 18 '23 at 11:49

1

This is entirely up to you, you could even do:

def lambda_handler(*args, **kwargs):

with event and context then being args[0] and args[1] respectively.

Lambda only cares that the lambda handler function takes at least two positional arguments.

answered May 18 '23 at 11:49

Paolo

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Is it good practice to add optional arguments to AWS lambda function?

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