从数据框中的字典中提取值

Question

我的数据框的其中一列是

 data['countries']

"[{'iso_3166_1': 'KR', 'name': 'South Korea'}]"
"[{'iso_3166_1': 'US', 'name': 'United States of America'}]"

如何仅提取国家名称：'South Korea','United States of America'等

Answer 1

import json
import numpy as np

countries = [ json.loads(c.replace("'", '"')) for c in data['countries'] if not np.isnan(c)]
country_names = [cn for cn[0]['name'] in countries]

输出将是：

>>> ['South Korea', 'United States of America']

Answer 2

如果您不想更改DataFrame，而只是解析其中包含的字符串的内容，则可以使用split。

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或：

>>> a = "[{'iso_3166_1': 'KR', 'name': 'South Korea'}]"
>>> a.split("'name': ")[1].split("'")[1]
'South Korea'

Answer 3

这应该有效

data['countries'] = data['countries'].apply(lambda x: eval(x))
data['countries'].apply(lambda x: x[0]['name'])

输出

0                 South Korea
1    United States of America
Name: 1, dtype: object

---

list(data[1].apply(lambda x: x[0]['name']))

输出

['South Korea', 'United States of America']