pandas sum 两列数据合并保留Nan

From the documentation pandas.DataFrame.sum By default, the sum of an empty or all-NA Series is 0. >>> pd.Series([]).sum() # min_count=0 is the default 0.0 This can be controlled with the min_count parameter. For example, if you’d like the sum of an empty series to be NaN, pass min_count=1. Change your code to data.loc[:,'Sum'] = data.loc[:,['Surf1','Surf2']].sum(axis=1, min_count=1) 原文 https://stackoverflow.com/questions/61636049/pandas-sum-of-two-columns-dealing-with-nan-values-correctly