Adding dataframe column with frequency counts for several pre-specified words in R

Question

I have a dataframe of thousands of news articles that looks like this:

id	text	date
1	newyorktimes leaders gather for the un summit in next week to discuss	1980-1-18
2	newyorktimes opinion section what the washingtonpost got wrong about	1980-1-22
3	a journalist for the washingtonpost went missing while on assignment	1980-1-22
4	washingtonpost president carter responds to criticisms on economic decline	1980-1-28
5	newyorktimes opinion section what needs to be down with about the rats	1980-1-29

I want to produce an additional column that has the combined counts for several specific words in the articles themselves. Let's say I want to know how many times "newyorktimes", "washingtonpost", and "the" appear in each article. I would want a separate column added to the dataframe adding the counts for that row. Like this:

id	text	date	wordlistcount
1	newyorktimes leaders gather for the un summit in next week to discuss	1980-1-18	2
2	newyorktimes opinion section what the washingtonpost and newyorktimes got wrong	1980-1-22	4
3	a journalist for the washingtonpost went missing while on assignment	1980-1-22	2
4	washingtonpost president carter responds to criticisms on economic decline	1980-1-28	1
4	newyorktimes opinion section what needs to be done with about the rats	1980-1-29	2

How can I accomplish this? Any help would be greatly appreciated.

Answer 1

In stringr, with str_count:

library(stringr)
library(dplyr)
words = c("newyorktimes", "washingtonpost", "the")
df %>% 
  mutate(wordlistcount = str_count(text, str_c("\\b", words, "\\b", collapse = "|")))




#   id                                                                       text      date wordlistcount
# 1  1      newyorktimes leaders gather for the un summit in next week to discuss 1980-1-18             2
# 2  2       newyorktimes opinion section what the washingtonpost got wrong about 1980-1-22             3
# 3  3       a journalist for the washingtonpost went missing while on assignment 1980-1-22             2
# 4  4 washingtonpost president carter responds to criticisms on economic decline 1980-1-28             1
# 5  5     newyorktimes opinion section what needs to be down with about the rats 1980-1-29             2