Leetcode 999. Available Captures for Rook

class Solution:
    def numRookCaptures(self, board: List[List[str]]) -> int:
        rook = [0, 0]
        ans = 0
        for i in range(8):
            for j in range(8):
                if board[i][j] == 'R':
                    rook[0], rook[1] = i, j
        for k in range(rook[1], 0, -1):  # left
            if board[rook[0]][k] == 'p':
                ans += 1
                break
            elif board[rook[0]][k] == 'B':
                break
        for k in range(rook[1], 8):  # right
            if board[rook[0]][k] == 'p':
                ans += 1
                break
            elif board[rook[0]][k] == 'B':
                break
        for k in range(rook[0], 0, -1):  # up
            if board[k][rook[1]] == 'p':
                ans += 1
                break
            elif board[k][rook[1]] == 'B':
                break
        for k in range(rook[1], 8):  # bottom
            if board[k][rook[1]] == 'p':
                ans += 1
                break
            elif board[k][rook[1]] == 'B':
                break
        return ans