如何在 pandas 数据框的列中用零代替NaN值? [英] How to replace NaN values by Zeroes in a column of a Pandas Dataframe?
问题描述
我有一个如下所示的Pandas数据框:
I have a Pandas Dataframe as below:
itm Date Amount
67 420 2012-09-30 00:00:00 65211
68 421 2012-09-09 00:00:00 29424
69 421 2012-09-16 00:00:00 29877
70 421 2012-09-23 00:00:00 30990
71 421 2012-09-30 00:00:00 61303
72 485 2012-09-09 00:00:00 71781
73 485 2012-09-16 00:00:00 NaN
74 485 2012-09-23 00:00:00 11072
75 485 2012-09-30 00:00:00 113702
76 489 2012-09-09 00:00:00 64731
77 489 2012-09-16 00:00:00 NaN
当我尝试将函数应用于Amount列,我得到以下错误:
When I try to apply a function to the Amount column, I get the following error:
ValueError: cannot convert float NaN to integer
我尝试使用数学模块
中的.isnan应用函数。我尝试了pandas .replace属性
。来自pandas 0.9
的稀疏数据属性我也尝试过如果NaN == NaN语句功能。
我也看过这篇文章如何在查看其他文章时,如何在R数据帧中用零替换NA值?
我尝试过的所有方法均无效或无法识别NaN。
任何提示或解决方案将不胜感激。
I have tried applying a function using .isnan from the Math Module I have tried the pandas .replace attribute I tried the .sparse data attribute from pandas 0.9 I have also tried if NaN == NaN statement in a function. I have also looked at this article How do I replace NA values with zeros in an R dataframe? whilst looking at some other articles. All the methods I have tried have not worked or do not recognise NaN. Any Hints or solutions would be appreciated.
推荐答案
我相信 DataFrame.fillna()
会为您完成此操作。
I believe DataFrame.fillna()
will do this for you.
示例:
In [7]: df
Out[7]:
0 1
0 NaN NaN
1 -0.494375 0.570994
2 NaN NaN
3 1.876360 -0.229738
4 NaN NaN
In [8]: df.fillna(0)
Out[8]:
0 1
0 0.000000 0.000000
1 -0.494375 0.570994
2 0.000000 0.000000
3 1.876360 -0.229738
4 0.000000 0.000000
到仅在一栏中填写NaN,仅选择该列。在这种情况下,我使用的是inplace = True实际更改df的内容。
To fill the NaNs in only one column, select just that column. in this case I'm using inplace=True to actually change the contents of df.
In [12]: df[1].fillna(0, inplace=True)
Out[12]:
0 0.000000
1 0.570994
2 0.000000
3 -0.229738
4 0.000000
Name: 1
In [13]: df
Out[13]:
0 1
0 NaN 0.000000
1 -0.494375 0.570994
2 NaN 0.000000
3 1.876360 -0.229738
4 NaN 0.000000
编辑:
要避免使用 SettingWithCopyWarning
,请使用内置的列专用功能:
To avoid a SettingWithCopyWarning
, use the built in column-specific functionality:
df.fillna({1:0}, inplace=True)
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