[FIXED] How to iterate through many columns for a value that is not NaN using Python

Issue

I have an empty column that is dependent on other 4 columns in the same df. Each row only contain the same string or NaN so I want to grab the first string that pops up in the columns.

I want to iterate through the 4 columns and if one of them contain a value that is not NaN, I want to print it in empty, if they're all NaN then I want empty to be NaN.

empty	1	2	3	4
	NaN	NaN	apple	NaN
	duck	NaN	duck	NaN
	NaN	NaN	NaN	NaN

This is my desired outcome.

empty	1	2	3	4
apple	NaN	NaN	apple	NaN
duck	duck	NaN	duck	NaN
NaN	NaN	NaN	NaN	NaN

Solution

Try .bfill(axis=1):

df["Empty"] = df.loc[:, "1":].bfill(axis=1)["1"]
print(df)

Prints:

   Empty     1   2      3   4
0  apple   NaN NaN  apple NaN
1   duck  duck NaN   duck NaN
2    NaN   NaN NaN    NaN NaN

Answered By - Andrej Kesely