对键值对匹配的嵌套对象中的值求和

def sum_nested_values(obj):
    if isinstance(obj, dict):
        total_sum = 0
        for value in obj.values():
            if isinstance(value, (int, float)):
                total_sum += value
            elif isinstance(value, dict):
                total_sum += sum_nested_values(value)
        return total_sum
    else:
        return "Error: Input is not a dictionary."

# 示例用法
nested_obj = {
    'a': 1,
    'b': {
        'c': 2,
        'd': {
            'e': 3,
            'f': 4
        }
    },
    'g': 5
}

result = sum_nested_values(nested_obj)
print(result)  # 输出：15