R从字符串中删除最后一个字 [英] R remove last word from string

问题描述

我正在尝试做某事但不记得/找到答案。我从人口普查局获得了一个城市名称列表，他们把城市的类型放在了结尾处，这使得我的 match（）。

I'm trying to do something but can't remember/find the answer. I have a list of city names from the Census Bureau and they put the city's type on the end which is messing up my match().

我想这样做：

Middletown Township
Sunny Valley Borough
Hillside Village

纳入：

into this:

Middletown
Sunny Valley
Hillside

有什么建议？理想情况下，我也想知道R中是否有 lastIndexOf（）函数。

Any suggestions? Ideally I'd also like to know if there's a lastIndexOf() function in R.

这里是dput：

Here's the dput:

> dput(df1)
structure(list(id = c(1, 2, 3), city = structure(c(2L, 3L, 1L
), .Label = c("Hillside Village", "Middletown Township", "Sunny Valley Borough"
), class = "factor")), .Names = c("id", "city"), row.names = c(NA, 
-3L), class = "data.frame")

推荐答案

这会起作用：

This will work:

gsub("\\s*\\w*$", "", df1$city)
[1] "Middletown"   "Sunny Valley" "Hillside"   

它删除由一个或多个空格字符组成的任何子字符串，后跟任意数量的单词字符（空格，数字或下划线），然后是字符串的结尾。

It removes any substring consisting of one or more space chararacters, followed by any number of "word" characters (spaces, numbers, or underscores), followed by the end of the string.

这篇关于R从字符串中删除最后一个字的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！