如何在R中使用模糊匹配来加入数据？

Question

I have some subject and license data and would like to create a column that flags whether the license is an appropriate one given the subject listed. The additional challenge is that some teachers teach multiple subjects, separated by semi-colons and there are several acceptable subjects for each license.

I think I need to incorporate something like grep, but I'm not quite sure how to add this function while also joining the data from two tables.

Sample code

Below is an excerpt of my dataframe:

df1 <- data.frame(Subject = c("Spanish Language Arts; I teach all subjects for my students", 
"Math; Science", "Mathematics; ELA", "ELA", "Science;Math;English Language Arts", 
"Spanish Language Arts; I teach all subjects for my students",
 "Math", "Science;Social Studies;Mathematics;English Language Arts", "ELA", 
"English Language Arts"), 
Licensure = c("Content Area - Early Childhood (preK-Grade 3)", 
"Core Subjects (Grades EC-6) 1770", "Mathematics (Grades 7-12) 1706", 
"English Language Arts and Reading (Grades 7-12) 1709", "Core Subjects (Grades EC-6) 1770", 
"English Language Arts and Reading (Grades 7-12) 1709", 
"English Language Arts and Reading (Grades 7-12) 1709", 
"Content Area - Elementary Education (Grades 1-6)", 
"Mathematics (Grades 7-12) 1706", "Content Area - Elementary Education (Grades 1-6)"))

Here is the list I created that includes all of the licenses with the acceptable programs underneath each:

lic.subject_index <- list(
  "Content Area - Early Childhood (preK-Grade 3)" = c("I teach all subjects for my students", "Math", "Mathematics", "ELA", "English Language Arts", "Language Arts"),
  "Content Area - Elementary Education (Grades 1-6)" = c("I teach all subjects for my students", "Math", "Mathematics", "ELA", "English Language Arts", "Language Arts"),
  "Core Subjects (Grades EC-6) 1770" = c("I teach all subjects for my students", "Math", "Mathematics", "ELA", "English Language Arts", "Language Arts"),
  "English Language Arts and Reading (Grades 7-12) 1709" = c("ELA", "English Language Arts", "Language Arts"),
  "Mathematics (Grades 7-12) 1706" = c("Math", "Mathematics")
)

What I would like to be able to do is create a column that flags whether the subject/license combination is acceptable or not:

ideal.df <- data.frame(Subject = c("Spanish Language Arts; I teach all subjects for my students", 
"Math; Science", "Mathematics; ELA", "ELA", "Science;Math;English Language Arts", 
"Spanish Language Arts; I teach all subjects for my students", "Math", 
"Science;Social Studies;Mathematics;English Language Arts", "ELA", "English Language Arts"), 
Licensure = c("Content Area - Early Childhood (preK-Grade 3)", "Core Subjects (Grades EC-6) 1770", 
"Mathematics (Grades 7-12) 1706", "English Language Arts and Reading (Grades 7-12) 1709", 
"Core Subjects (Grades EC-6) 1770", "English Language Arts and Reading (Grades 7-12) 1709", 
"English Language Arts and Reading (Grades 7-12) 1709", "Content Area - Elementary Education (Grades 1-6)", 
"Mathematics (Grades 7-12) 1706", "Content Area - Elementary Education (Grades 1-6)"), 
flag = c("True", "True", "True", "True", "True", "False", "False", "True", "False", "True"))

Thank you in advance for any help you can provide!

Answer 1

Here is an option with tidyverse and fuzzyjoin

library(fuzzyjoin)
library(tidyverse)
out <- df1 %>%
       rownames_to_column('rn') %>% 
       separate_rows(Subject, sep = ';') %>% 
       stringdist_left_join(
         enframe(lic.subject_index, name = 'Licensure', value = 'Subject') %>% 
              unnest) %>% 
       group_by(rn = as.integer(rn)) %>%
       summarise(ind = any(!is.na(Licensure.y))) %>%
       ungroup %>% 
       pull(ind) %>% 
       mutate(df1, flag = .)
out$flag
#[1]  TRUE  TRUE  TRUE  TRUE  TRUE FALSE FALSE  TRUE FALSE  TRUE

-checking OP''s ideal output

as.logical(ideal.df$flag)
#[1]  TRUE  TRUE  TRUE  TRUE  TRUE FALSE FALSE  TRUE FALSE  TRUE