Thank you! Now I solved the issue) I didn't use print() here before this Kata.

a or b might be nil or null or None or nothing (except in C++, Elixir, Haskell, PureScript, Pascal, Perl, R, Rust, Shell).

Yes, try printing the input.

Traceback (most recent call last):
File "/workspace/default/src/codewars-test/codewars_test/test_framework.py", line 111, in wrapper
func()
File "tests.py", line 25, in basics
test.assert_equals(comp(a1, a2), False)
File "/workspace/default/solution.py", line 4, in comp
array2.sort()
AttributeError: 'NoneType' object has no attribute 'sort'

My func can pass 105 testcases... But something ruine my code. I guess it someting like Null or None instead of Array2

Sorry, won't argue there, but... using "same" with quotes, and having more then 10 comments regarding the universal concept of 'multiplicities' in the kata discourse...
IMHO repeating 20 times the "same" confusing stuff doesn't make it clear..

Please read this: https://docs.codewars.com/training/troubleshooting#print-input