map applies a function to every element of an iterable. Sometimes these functions are very simple operations; for example, if I wanted to double every number in a list. It's wasteful to define an entire new function (with the def keyword) just for this one simple operation. Lambda creates a callable function that we can use. Here's an example of how we could create that and use it with map. numbers = [1, 5, 20, 50] map(lambda x:x * 2, numbers) More on reddit.com

This is a typical example for beginners: x=lambda n:2*n print(x(7)) Otherwise I would create a function: def dbl(n): return 2*n print(dbl(7)) Of course: I can write simply 2*7, but the idea is to save a complex formula in an object once, and reuse it several times. More on discuss.python.org

I kinda view them as a shorthand, not required but sometimes nice to have. Stuff like sorting list of lists by index makes sense to use lambdas, but you can fall into the trap of having unreadable oneliners, so some self-restraint is required. If you meant the AWS Lambda the service, I like it IF you have a good way of managing dependancies or are comfortable with using the standard lib for everything. More on reddit.com

Lambdas for the most part should be very simple. Powertools is great, I love their logger. Unit testing is also good, but at the end of the day the Lambda should be as simple as “does it do its job? Yes? Great” and usually not have to test for a huge range of scenarios. Lambda maximum execution time is 15 minutes, which I’ve always found kind of nuts… if your Lambda needs to take longer than like 3 minutes to complete its task, then maybe the task was not right for a serverless pattern. That’s just my personal thoughts More on reddit.com