lammmmb

I think it will take more time as sorting is generally O(nlogn) while you can compare len(a), len(b) faster than sorting.

And that's why you use CodeWars.

thank you both, I will investigate

It depends on what's called built-in. It's the standard library. Even though there can always be non-standard implementations of any language, relying on the standard library is normal.
As for non-standard libraries on CW: https://github.com/Codewars/codewars.com/wiki/Language-Python

yep, sure: https://docs.python.org/3/library/ : everything that is not labelled "Built-in..." is a module present by default (may depend on the python version/installer for some of them, I guess)

@B4B, sorry 'bout the flag... what python modules are present by default on CW? is there a list of such defaults for each language? thanks

spoiler flag, guys...

@Ashish8796: they are not "built-ins", but the related module is present by default so they always are at hand, if that's your question.

i tried thats why i asked.

beutiful <3