Magic Squares In Grid LeetCode solution in Python

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class Solution:
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    digits = {1, 2, 3, 4, 5, 6, 7, 8, 9}
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    @classmethod
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    def magic_3_3(cls, square: List[List[int]]) -> bool:
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        if set(sum(square, [])) != Solution.digits:
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            return False
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        sum_row0 = sum(square[0])
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        for r in range(1, 3):
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            if sum(square[r]) != sum_row0:
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                return False
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        if any(sum(col) != sum_row0 for col in zip(*square)):
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            return False
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        sum_main_diagonal = sum_second_diagonal = 0
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        for i in range(3):
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            sum_main_diagonal += square[i][i]
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            sum_second_diagonal += square[i][2 - i]
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        return sum_main_diagonal == sum_second_diagonal == sum_row0
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    def numMagicSquaresInside(self, grid: List[List[int]]) -> int:
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        count = 0
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        rows, cols = len(grid), len(grid[0])
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        for r in range(rows - 2):
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            for c in range(cols - 2):
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                if Solution.magic_3_3(
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                    [grid[row_idx][c : c + 3] for row_idx in range(r, r + 3)]
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                ):
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                    count += 1
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        return count