It's because anonymous functions like that are very much inspired by the lambda calculus where you'd write λx. f x for python's lambda x: f(x) and it's just a "pythonization" of that syntax.

The description does not specify that nums will always have one or more numbers.

And it's usually a good practice to check that a value is not zero before dividing something by it.

I know, but it's one of the most efficient methods

😂 I feel the urge to put an api request to get the most accurate calculator to carry out this mathematical operations

Also, you don't have to create and publish the kata to ask if it's a good idea.

Ask on Discord#kata-ideas first.

No. This has been done.

ETA: if you have to restrict native functionality, don't make it into a kata. It almost never ends well.

It's okay, don't give up and you'll succeed.