Python函数根据嵌套字典中的字符串值对整数值求和？

def sum_integers(dictionary):
    total_sum = 0

    for value in dictionary.values():
        if isinstance(value, int):
            total_sum += value
        elif isinstance(value, dict):
            total_sum += sum_integers(value)

    return total_sum

nested_dict = {
    'a': 1,
    'b': {
        'x': 2,
        'y': {
            'i': 3,
            'j': 4
        }
    },
    'c': 5
}

result = sum_integers(nested_dict)
print(result)  # 输出：15