K Highest Ranked Items Within a Price Range

class Solution:
    def highestRankedKItems(self, grid: List[List[int]], pricing: List[int], start: List[int], k: int) -> List[List[int]]:
        m, n = len(grid), len(grid[0])
        dirs = [(0, 1), (1, 0), (0, -1), (-1, 0)]
        queue = deque([start])
        res = []
        if pricing[0]<=grid[start[0]][start[1]]<=pricing[1]:
            res.append(start)
        vis = set([(start[0], start[1])])
        while queue:
            sz = len(queue)
            tmp = []
            for _ in range(sz):
                a, b = queue.pop()
                for x, y in dirs:
                    if 0<=a+x<m and 0<=b+y<n and (a+x, b+y) not in vis and grid[a+x][b+y] > 0:
                        queue.appendleft([a+x, b+y])
                        vis.add((a+x, b+y))
                        if pricing[0]<=grid[a+x][b+y]<=pricing[1]:
                            tmp.append([a+x, b+y])
            tmp.sort(key=lambda x: (grid[x[0]][x[1]], x[0], x[1]))
            res += tmp
            if len(res) >= k:
                break

        return res[:k]