Positional indexing with NA values-CodePudding

I need to index the dataframe from positional index, but I got NA values in previous operation and I wanna preserve it. How could I achieve this?

df1

NaN
1
NaN
NaN
NaN
6

df2

df3

0 15
1 17

The output I want

NaN
15
NaN
NaN
NaN
17

df2.iloc(df1)

IndexError: indices are out-of-bounds

.iloc method in this case drive to a unbound error, I think .iloc is not available here. df3 is another output generated by .loc, but I don't know how to add NaN between them. If you can achieve output by using df1 and df3 is also ok

CodePudding user response：

If df1 and df2 has same index values use for replace non missing values by values from another DataFrame DataFrame.mask with DataFrame.isna:

df1 = df2.mask(df1.isna())
print (df1)
    col
0   NaN
1  15.0
2   NaN
3   NaN
4   NaN
5  17.0