在矩阵python中查找矩阵的中间索引

def find_middle_index(matrix):
    num_rows = len(matrix)
    num_cols = len(matrix[0])

    for i in range(num_rows):
        left_sum = 0
        right_sum = sum(matrix[i]) - matrix[i][0]
        
        if left_sum == right_sum:
            return i
        
        for j in range(1, num_cols):
            left_sum += matrix[i][j-1]
            right_sum -= matrix[i][j]
            
            if left_sum == right_sum:
                return i
    
    return -1