使用平均值填充 pandas 数据框中的缺失值
Fill in missing values in pandas dataframe using mean
datetime
2012-01-01 125.5010
2012-01-02 NaN
2012-01-03 125.5010
2013-01-04 NaN
2013-01-05 125.5010
2013-02-28 125.5010
2014-02-28 125.5010
2016-01-02 125.5010
2016-01-04 125.5010
2016-02-28 NaN
我想通过使用从数据集计算的气候学来填充此数据框中的 missig 值，即通过平均其他年份的 28th feb 值来填充缺失的 28th feb 2016 值。我该怎么做？
您可以使用 groupby by month and day and transform with fillna mean:
print df.groupby([df.index.month, df.index.day]).transform(lambda x: x.fillna(x.mean()))
datetime
2012-01-01 125.501
2012-01-02 125.501
2012-01-03 125.501
2013-01-04 125.501
2013-01-05 125.501
2013-02-28 125.501
2014-02-28 125.501
2016-01-02 125.501
2016-01-04 125.501
2016-02-28 125.501
datetime
2012-01-01 125.5010
2012-01-02 NaN
2012-01-03 125.5010
2013-01-04 NaN
2013-01-05 125.5010
2013-02-28 125.5010
2014-02-28 125.5010
2016-01-02 125.5010
2016-01-04 125.5010
2016-02-28 NaN
我想通过使用从数据集计算的气候学来填充此数据框中的 missig 值，即通过平均其他年份的 28th feb 值来填充缺失的 28th feb 2016 值。我该怎么做？
您可以使用 groupby by month and day and transform with fillna mean:
print df.groupby([df.index.month, df.index.day]).transform(lambda x: x.fillna(x.mean()))
datetime
2012-01-01 125.501
2012-01-02 125.501
2012-01-03 125.501
2013-01-04 125.501
2013-01-05 125.501
2013-02-28 125.501
2014-02-28 125.501
2016-01-02 125.501
2016-01-04 125.501
2016-02-28 125.501