一尘不染

Numpy Select返回布尔错误消息

python

我想在路径中找到匹配的字符串,并使用np.select创建一个新列,其中的标签取决于我找到的匹配项。

这是我写的

import numpy as np
conditions  = [a["properties_path"].str.contains('blog'),
               a["properties_path"].str.contains('credit-card-readers/|machines|poss|team|transaction_fees'),
               a["properties_path"].str.contains('signup|sign-up|create-account|continue|checkout'),
               a["properties_path"].str.contains('complete'),
               a["properties_path"] == '/za/|/',
              a["properties_path"].str.contains('promo')]
choices     = [ "blog","info_pages","signup","completed","home_page","promo"]
a["page_type"] = np.select(conditions, choices, default=np.nan)

但是,当我运行此代码时,出现以下错误消息:

ValueError:condlist中的无效条目0:应为boolean ndarray

这是我的数据样本

3124465                                       /blog/ts-st...
3124466                                       /card-machines
3124467                                       /card-machines
3124468                                       /card-machines
3124469                               /promo/our-gift-to-you
3124470                                   /create-account/v1
3124471                                          /za/signup/
3124472                                   /create-account/v1
3124473                                             /sign-up
3124474                                                 /za/
3124475                                        /sign-up/cart
3124476                                           /checkout/
3124477                                            /complete
3124478                                       /card-machines
3124479                                       /continue
3124480                             /blog/article/get-car...
3124481                             /blog/article/get-car...
3124482                                          /za/signup/
3124483                                 /credit-card-readers
3124484                                          /signup
3124485                                 /credit-card-readers
3124486                                   /create-account/v1
3124487                                 /credit-card-readers
3124488                                   /point-of-sale-app
3124489                                   /create-account/v1
3124490                                   /point-of-sale-app
3124491                                 /credit-card-readers

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2021-01-20

共1个答案

一尘不染

.str方法在对象列上操作。此类列中可能包含非字符串值,结果是这些行而不是pandas返回。然后抱怨,因为这不是布尔值。NaN``False``np

幸运的是,有一个参数可以解决这个问题: na=False

a["properties_path"].str.contains('blog', na=False)

或者,您可以将条件更改为:

a["properties_path"].str.contains('blog') == True
#or
a["properties_path"].str.contains('blog').fillna(False)

样品

import pandas as pd
import numpy as np

df = pd.DataFrame({'a': [1, 'foo', 'bar']})
conds = df.a.str.contains('f')
#0      NaN
#1     True
#2    False
#Name: a, dtype: object

np.select([conds], ['XX'])
#ValueError: invalid entry 0 in condlist: should be boolean ndarray

conds = df.a.str.contains('f', na=False)
#0    False
#1     True
#2    False
#Name: a, dtype: bool

np.select([conds], ['XX'])
#array(['0', 'XX', '0'], dtype='<U11')
2021-01-20