I have a CSV with these data:
List Rank.A List Rank.B List Rank.C
a 4 a 8 b 3
b 5 e 5 e 9
c 7 f 5 r 1
I want to create a new csv in which there is only a one-column with a name List with a unique value and there is 3 more columns of "Rank.A", "Rank.B", "Rank.C" in same list. Suppose if Rank.A not listed with any row of List than it display blank. I want data in this format
List Rank.A Rank.B Rank.C
a 4 8
b 5 3
c 7
e 5 9
f 5
r 1
Can you please help me in that?