Drop a word in a column of data table in R

Question

I have a data table that looks like

            location                county
1:  40.96875_-72.78125      Walla Walla County
2:  41.15625_-90.65625           Mercer County
3:  41.21875_-90.65625           Mercer County
4:  41.28125_-89.84375           Bureau County
5:  41.28125_-89.90625            Henry County

How can I, efficiently, drop the word "county" in the county column, so, only the name of counties is left in there.

Answer 1

We can use sub to select one or more spaces followed by characters that are not a space until the end ( $ ) of the string, replace with blanks ( "" )

dt1[, county := sub("\\s+[^ ]+$", "", county)]
dt1$county
#[1] "Walla Walla" "Mercer"      "Mercer"      "Bureau"      "Henry"      

If it is specific to 'County' word, then

dt1[, county := sub("\\s+County$", "", county)]

Answer 2

或者，您可以使用 de gsub函数，将单词"county"替换为"" ：

df$county = gsub("county", "", df$county)