i used "is" but still doesn't work!

Yes

False == Null == 0 == {} == []

are all true

because False == 0 is True ?!

my code was wrong, but now, after fixed it, he is correct

Your seventh column has two ones, and your eighth column has two eights. So, I'm sorry to say, but your answer is wrong.

Correct solution:

[6,4,5,1,9,8,2,7,3]
[1,2,7,3,4,6,5,9,8]
[8,9,3,2,7,5,4,6,1]
[5,1,4,6,2,7,3,8,9]*
[2,3,8,4,1,9,6,5,7]
[7,6,9,8,5,3,1,4,2]*
[4,5,1,7,8,2,9,3,6]
[9,8,6,5,3,1,7,2,4]
[3,7,2,9,6,4,8,1,5]
             * *

I tried to do a backtraking algorithm to solve this kata, I tested several times to see if the algorithm was working correctly (I used another algorithm to check if they were right), and they were all correct, but when I submitted my solution to this kata he said that "the value was not expected". Why?

why is my code deleting the False?????? I tried everything to fix this error but nothing worked