Pygame Tic Tak Toe Logic? How Would I Do It

I am trying to make a tic tak toe game with pygame and I was wondering how would I do the logic here is what I have so far. VIDEO < I only have it when I click on the middle button it will display the player 2 x on the screen and then the image that is hovering over my mouse will turn into O for player 1 turn to go BUT my question is how would I do the logic like if player 1 gets 3 in a row or player 2 gets 3 across in a row I am really confused on this and I need someone to walk me throw it