Hi

Why is it suited for python 3.10 ? what's the feature of it involved in the refinement of the code ?

Thanks

I am in the same position and I understand that the result must be ?.

Solution 1: ( "!" are the positions that one can safelly call game.open. "X" upper case is the first guess.
x 2 3 x 2
2 ! x x 2
! x 3 3 2
! ! ! 2 x
! ! X 2 1
In this case we found one possible solution.

Solution 2:
x 2 3 x 2
2 x ! x 2
! ! 3 3 2
? ! X 2 x
? ? ! 2 1
One mine in any of the ? will also be a solution, so we have 3 more possibilities.

As we end with 4 possible solutions the return should be "?"

The second solution is invalid. Look at the left-bottom coner, if no mines around it, it will be "0", not "?".
And if your code is clever enough, you can open a and b positions safely:

1 1 1 1 1
x 2 3 x 2
2 ? ? x 2
a b 3 3 2 
? ? ? 2 x 
? ? ? 2 1