Retrieving sentence score based on values of words in a dictionary

Question

Edited df and dict

I have a data frame containing sentences:

df <- data_frame(text = c(\"I love pandas         


        

Answer 1

A bit of double looping via sapply and gregexpr:

res <- sapply(dict$word, function(x) {
  sapply(gregexpr(x,df$text),function(y) length(y[y!=-1]) )
})
rowSums(res * dict$score)
#[1]  2 -2

This also accounts for when there is multiple matches in a single string:

df <- data.frame(text = c("I love love pandas", "I hate monkeys"))
# run same code as above
#[1]  3 -2