I tried to read the post you gave me, but there are like hundreds of things. I tried some and it didn't work. I think its because my column names are numbers.
my df is like this:
1 2 3 x
1 1.2 3.2 4.4 1
2 5.4 2.2 1.4 3
3 5.6 3.4 2.3 1
I want to create a new column (y) with the value of the reference column name for every rows. my expected result
1 2 3 x y
1 1.2 3.2 4.4 1 1.2
2 5.4 2.2 1.4 3 1.4
3 5.6 3.4 2.3 1 5.6
