基于数组键求和的多维数组

# 定义一个二维数组（矩阵）
matrix = [
    [1, 2, 3],
    [4, 5, 6],
    [7, 8, 9]
]

# 根据列索引求和
def sum_by_key(matrix, key):
    total = 0
    for row in matrix:
        total += row[key]
    return total

# 示例：求第二列的和
result = sum_by_key(matrix, 1)
print("第二列的和:", result)  # 输出: 第二列的和: 15

def safe_sum_by_key(matrix, key):
    total = 0
    for row in matrix:
        if isinstance(row[key], (int, float)):
            total += row[key]
        else:
            print(f"警告: 元素 {row[key]} 不是数字，跳过")
    return total

# 示例：包含非数字元素的矩阵
matrix_with_non_numeric = [
    [1, 2, 3],
    [4, "a", 6],
    [7, 8, 9]
]

result = safe_sum_by_key(matrix_with_non_numeric, 1)
print("第二列的和（安全模式）:", result)  # 输出: 第二列的和（安全模式）: 10