如何根据R中的一列列表将一个数据框中的值汇总到另一个数据框中

Question

I am stuck here and believe I am overcomplicating this problem...

I am trying to sum a "Number" by a categorical variable "County" by detecting it in a list of counties separated by a ",".

Is there a way to do this in base and/or dplyr? I tried some variations of str_detect and filter, but can't seem to figure this out.

Looking to the code below at data frames d1-d3:

• d1 shows the "Number" associated with each "County"
• d2 shows each "County" list to sum
• d3 should show the total sum of each "County" listed

d1 <- data.frame(County =  c("a", "b", "c", "d") ,
                Number = c(1000, 2000, 3000, 4000))
d1

  County Number
1      a   1000
2      b   2000
3      c   3000
4      d   4000

d2 <- data.frame(County =  c("a, b", "b, c", "c", "d, a", "a, c, d, b"))

d2

 County
1   a, b
2   b, c
3      c
4   d, a
5   a, c, d, b


d3 <- 

d3 

County           Total 
1   a, b         3000
2   b, c         5000
3      c         3000
4   d, a         5000
5   a, c, d, b   10000

Answer 1

Do Either of these

BaseR

d2$Total <- Map(f= function(x) sum(d1$Number[match(x, d1$County)]), strsplit(d2$County, ", "))

> d2
      County Total
1       a, b  3000
2       b, c  5000
3          c  3000
4       d, a  5000
5 a, c, d, b 10000

tidyverse

library(tidyverse)
d2 %>% mutate(Total = map(str_split(County, ", "), ~ sum(d1$Number[match(.x, d1$County)])))

      County Total
1       a, b  3000
2       b, c  5000
3          c  3000
4       d, a  5000
5 a, c, d, b 10000