提取存储在数据帧的列中的键的值?

时间:2019-04-17 13:10:08

标签: python

我有一个如下所示的数据框:

user_id event_desc
100013  {'firebase_screen': '/product-popup', 'banner_id': '9260'}
100022  {'firebase_screen': '/product-popup', 'banner_id': '9152'}
100076  {'firebase_screen_id': '-1531185473150377061'}
100076  {'banner_id': '8567', 'firebase_screen': '/product-popup'}

我正在尝试获取键banner_id的值。

因此,输出如下:

user_id event_desc                                            banner_id
100013  {'firebase_screen': '/product-popup', 'banner_id': '9260'}  9260
100022  {'firebase_screen': '/product-popup', 'banner_id': '9152'}  9151
100076  {'firebase_screen_id': '-1531185473150377061'}               Nan
100076  {'banner_id': '8567', 'firebase_screen': '/product-popup'}  8567

我正在使用以下代码。

df['banner_id'] = df['event_desc'].apply(lambda x: x.get('banner_id'))

出现错误:

'str'对象没有属性'get'

2 个答案:

答案 0 :(得分:0)

只要它们不存储为字符串,它就可以工作:

import pandas as pd

df = pd.DataFrame([
[100013,  {'firebase_screen': '/product-popup', 'banner_id': '9260'}],
[100022,  {'firebase_screen': '/product-popup', 'banner_id': '9152'}],
[100076 , {'firebase_screen_id': '-1531185473150377061'}],
[100076 , {'banner_id': '8567', 'firebase_screen': '/product-popup'}]], columns =['user_id', 'event_desc'])


df['banner_id'] = df['event_desc'].apply(lambda x: x.get('banner_id'))   

根据您的错误,我的猜测是列不是字典列,而是字符串列:

import pandas as pd

df = pd.DataFrame([
[100013,  "{'firebase_screen': '/product-popup', 'banner_id': '9260'}"],
[100022,  "{'firebase_screen': '/product-popup', 'banner_id': '9152'}"],
[100076 , "{'firebase_screen_id': '-1531185473150377061'}"],
[100076 , "{'banner_id': '8567', 'firebase_screen': '/product-popup'}"]], columns =['user_id', 'event_desc'])


df['banner_id'] = df['event_desc'].apply(lambda x: x.get('banner_id'))

AttributeError: 'str' object has no attribute 'get'

因此,您需要使用:

import pandas as pd
import ast

df = pd.DataFrame([
[100013,  "{'firebase_screen': '/product-popup', 'banner_id': '9260'}"],
[100022,  "{'firebase_screen': '/product-popup', 'banner_id': '9152'}"],
[100076 , "{'firebase_screen_id': '-1531185473150377061'}"],
[100076 , "{'banner_id': '8567', 'firebase_screen': '/product-popup'}"]], columns =['user_id', 'event_desc'])


df['banner_id'] = df['event_desc'].apply(lambda x: ast.literal_eval(x).get('banner_id')) 

附加:

import pandas as pd
import ast


def eval_code(code):
    parsed = ast.parse(code, mode='eval')
    fixed = ast.fix_missing_locations(parsed)
    compiled = compile(fixed, '<string>', 'eval')
    return eval(compiled)


df = pd.DataFrame([
[100013,  "{'firebase_screen': '/product-popup', 'banner_id': '9260'}"],
[100022,  "{'firebase_screen': '/product-popup', 'banner_id': '9152'}"],
[100076 , "{'firebase_screen_id': '-1531185473150377061'}"],
[100076 , "{'banner_id': '8567', 'firebase_screen': '/product-popup'}"]], columns =['user_id', 'event_desc'])


df['banner_id'] = df['event_desc'].apply(lambda x: eval_code(x).get('banner_id'))     

答案 1 :(得分:0)

df['banner_id'] = df['event_desc'].apply(lambda x: ast.literal_eval(str(x)).get('banner_id'))