r语言 - 从字符串中删除最后n个字符

Question

我想从字符串中删除第三和第四个字符。

下面是一些示例数据:

HS0202
HS0902
MV0100
SUE0300

我需要返回像这样的东西

HS02
HS02
MV00
SUE00

Answer 1

使用gsub():

gsub("..(?=..$)", "", chrs, perl = TRUE)
# "HS02"  "HS02"  "MV00"  "SUE00"

或与stringr::str_remove():

library(stringr)
str_remove(chrs, "..(?=..$)")
# "HS02"  "HS02"  "MV00"  "SUE00"

Answer 2

您可以从最后的第一个字符提取到第四个字符，并粘贴在最后一个字符上，如下所示:

have <- c('HS0202', 'HS0902', 'MV0100', 'SUE0300')
want <- paste0(substring(have,1,nchar(have)-3),substring(have,nchar(have)))

Answer 3

Usingstringi:

library(stringi)
stri_sub_replace(x, from = -4, to = -3, value = "")
[1] "HS02"  "HS02"  "MV00"  "SUE00"

或与stringr:

library(stringr)
str_sub(x, start = -4, end = -3) <- ""

x <- c("HS0202", "HS0902", "MV0100", "SUE0300")