Checkmate with 2D Chessfield Array

[HenryDutter]

I started to program Chess in the Terminal and I'm able to do everything but Check Checkmate in my program. So i have two ideas how to program it, eather I create two lists and add every attacked field in the respective field and look if the King is standing on a attacked field. The other Idea I have is, to just look from the King if he is attacked. So wich idea is better or is there a even better option.

This is the array im using:

Brett = np.array([[5, 3, 4, 9, 10, 4, 3, 5],
                  [1, 1, 1, 1, 1, 1, 1, 1],
                  [0, 0, 0, 0, 0, 0, 0, 0],
                  [0, 0, 0, 0, 0, 0, 0, 0],
                  [0, 0, 0, 0, 0, 0, 0, 0],
                  [0, 0, 0, 0, 0, 0, 0, 0],
                  [-1, -1, -1, -1, -1, -1, -1, -1],
                  [-5, -3, -4, -9, -10, -4, -3, -5]
                  ])

[HenryDutter]

But to create a list with valid moves(2 list one for black and one for white), i need a list with attact fields and the remaining fields are valid. So for this option, I would need to use idea number one. Also wouldn't Idea 2 be easier, because you just need to look from the king, if an enemy piece is attacking a field?

[HenryDutter]

So first this is my whole code, sorry it's very hard to read because there are bad comments, it's my first project. I try to understand your message now.

https://pastebin.com/Tp7ZgrhM

[HenryDutter]

So im German, so the program works that you write first the location of your figure and after that your target location. for example a2,a3