How do I group together string rows with partial matching strings and then sum them together?

Question

Artist	Points
Notorious BIG	34
Notorious BIG feat. blah blah	42
2pac	20
Dr.Dre feat. 2pac	30

I would like to group and sum by Artist for a table to look like so:

Artist	Points
Notorious BIG	76
2pac	50

Answer 1

I think the best way to approach this is to know which are the ones you want to combine since problem occurs when rows have multiple commonalities i.e.

Artist	Points
2pac	34
Dr. Dre feat. 2pac	100
Dr. Dre	80

You can specify the names of the rows you want to combine using the base R grepl function, and the dplyr functions, case_when and summarise.

library(dplyr)

df <- data.frame(Artist = c("Notorious BIG", "Notorious BIG feat. blah blah", "2pac", "Dr.Dre feat. 2pac"),
             Points = c(34, 42, 20, 30))
df <- df %>% 
  dplyr::mutate(Artist = case_when(
    grepl("2pac", Artist) ~ "2pac",
    grepl("Notorious BIG", Artist) ~ "Notorious BIG"),
                Artist = factor(Artist)) %>% 
  dplyr::group_by(Artist) %>% 
  dplyr::summarise(Points = sum(Points)) %>% 
  dplyr::ungroup()