python - 带有附加参数的自定义聚合原语？

Question

转换原语可以很好地处理附加参数。这是一个例子

def string_count(column, string=None):
    '''
    ..note:: this is a naive implementation used for clarity
    '''
    assert string is not None, "string to count needs to be defined"
    counts = [str(element).lower().count(string) for element in column]
    return counts


def string_count_generate_name(self):
    return u"STRING_COUNT(%s, %s)" % (self.base_features[0].get_name(),
                                      '"' + str(self.kwargs['string'] + '"'))


StringCount = make_trans_primitive(
    function=string_count,
    input_types=[Categorical],
    return_type=Numeric,
    cls_attributes={
        "generate_name": string_count_generate_name
    })

es = ft.demo.load_mock_customer(return_entityset=True)
count_the_feat = StringCount(es['transactions']['product_id'], string="5")
fm, fd = ft.dfs(
    entityset=es,
    target_entity='transactions',
    max_depth=1,
    features_only=False,
    seed_features=[count_the_feat])

输出:

                product_id  STRING_COUNT(product_id, "5")
transaction_id                                           
1                        5                              1
2                        4                              0
3                        3                              0
4                        3                              0
5                        4                              0

但是，如果我像这样修改并制作成聚合原语:

def string_count(column, string=None):
    '''
    ..note:: this is a naive implementation used for clarity
    '''
    assert string is not None, "string to count needs to be defined"
    counts = [str(element).lower().count(string) for element in column]
    return sum(counts)


def string_count_generate_name(self):
    return u"STRING_COUNT(%s, %s)" % (self.base_features[0].get_name(),
                                      '"' + str(self.kwargs['string'] + '"'))


StringCount = make_agg_primitive(
    function=string_count,
    input_types=[Categorical],
    return_type=Numeric,
    cls_attributes={
        "generate_name": string_count_generate_name
    })

es = ft.demo.load_mock_customer(return_entityset=True)
count_the_feat = StringCount(es['transactions']['product_id'], string="5")

我收到以下错误:

TypeError: new_class_init() missing 1 required positional argument: 'parent_entity'

功能工具是否支持带有附加参数的自定义聚合原语？

Answer 1

此处的问题是您的种子功能缺少参数。对于聚合原语，您需要指定要聚合的实体。在这种情况下，将聚合种子特征的构造更改为

count_the_feat = StringCount(es['transactions']['product_id'], es['sessions'], string="5")

将创建特征

sessions.STRING_COUNT(product_id, "5")

如预期。该功能将给出字符串“5”出现在每个 session ID 中的频率。