从句子中删除单词

Question

I have a dataframe containing text, I am trying to remove certain words from the text that are stored in a vector. Please help me achieve this!

stopwords <- c("today","hot","outside","so","its")
df <- data.frame(a = c("a1", "a2", "a3"), text = c("today the weather looks hot", "its so rainy outside", "today its sunny"))

Expected Output:

   a                        text          new_text
1 a1 Today the weather looks hot the weather looks
2 a2        its so rainy outside             rainy
3 a3             today its sunny             sunny

Answer 1

Paste all the stopwords together and use gsub to remove them.

df$new_text <- trimws(gsub(paste0(stopwords, collapse = "|"), "", df$text))
df
#   a                        text          new_text
#1 a1 today the weather looks hot the weather looks
#2 a2        its so rainy outside             rainy
#3 a3             today its sunny             sunny

Or with str_remove_all

stringr::str_remove_all(df$text, paste0(stopwords, collapse = "|"))

Just to be extra-safe add word boundaries around each stopwords so that, "so" from "something" or "some" is not replaced.

df$new_text <- trimws(gsub(paste0("\\b", stopwords, "\\b",
               collapse = "|"), "", df$text))