Finding the index or unique values from a dataframe column

Question

I have a dataframe

TableName Function Argument
A         func1    3
B         func1    4
A         func2    6
B         func2    2
C         func1    5
         


        

Answer 1

Using data.table:

setDT(data)[, .(Index = toString(.I)), TableName]
   TableName Index
1:         A  1, 3
2:         B  2, 4
3:         C     5