Question

这是我的数据集：

 offerid category countty   browserid   devid   click
0   887235  17714   e   Firefox        NaN      0
1   178235  21407   b   Mozilla        Desktop  0
2   518539  25085   a   Edge           NaN      0
3   390352  40339   c   Firefox       Mobile    0
4   472937  12052   d   Mozilla       Desktop   0

每次Firefox出现在'browserid'列中时，我需要用'Mobile'填充'devid'列中的'NaN'。这是我为实现这一目标而编写的代码。

if data['browserid'] == 'Firefox' :
    data['devid'].fillna('Mobile', inplace=True)

我遇到以下错误：

ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().

任何帮助都会得到帮助！

Answer 1

from io import StringIO
import pandas as pd

TESTDATA=StringIO(""" offerid category countty browserid devid click
0 887235 17714 e Firefox NaN 0
1 178235 21407 b Mozilla Desktop 0
2 518539 25085 a Edge NaN 0
3 390352 40339 c Firefox Mobile 0
4 472937 12052 d Mozilla Desktop 0""")

df = pd.read_csv(TESTDATA, sep=" ")
df = df.iloc[:,1:]

df.loc[df['browserid'] == 'Firefox','devid'] = df.loc[df['browserid'] == 'Firefox','devid'].fillna('Mobile')

Answer 2

此外，你可以这样做：

data.loc[data.browserid == "Firefox",'devid'] = 0 (or "NaN")

但问题的答案是你用一个字符串比较一个列......

Answer 3

   offerid  category countty browserid    devid  click
0   887235     17714       e   Firefox   Mobile      0
1   178235     21407       b   Mozilla  Desktop      0
2   518539     25085       a      Edge      NaN      0
3   390352     40339       c   Firefox  Mobile       0
4   472937     12052       d   Mozilla      NaN      0

Read data using pandas
import pandas as pd
df = pd.read_csv('stack_overflow.csv')
df.loc[(df['browserid']=='Firefox')&(df.devid.isnull()),'devid'] ='Mobile'

output 
   offerid  category countty browserid    devid  click
0   887235     17714       e   Firefox   Mobile      0
1   178235     21407       b   Mozilla  Desktop      0
2   518539     25085       a      Edge      NaN      0
3   390352     40339       c   Firefox   Mobile      0
4   472937     12052       d   Mozilla      NaN      0

Python - 如果语句错误

3 个答案: