如何根据r中单列中的给定短语进行筛选

Question

下面是示例数据。似乎很基本，但我在网上搜索没有得到明确的答案。在这种情况下，我如何创建一个新的数据帧，其中区域名称在末尾只有短语MSA，而不是MicroSA或其他可能性。

areaname <- c("Albany NY MSA", "Albany GA MSA", "Aberdeen SD MicroSA", "Reno NV MSA", "Fernley NV MicroSA", "Syracuse NY MSA")
Employment <- c(100,104,108,112,116,88)
testitem <- data.frame(areaname, Employment)

Answer 1

testitem %>%
filter(stringr::str_ends(areaname, "MSA"))

areaname Employment
1   Albany NY MSA        100
2   Albany GA MSA        104
3     Reno NV MSA        112
4 Syracuse NY MSA         88

Answer 2

另一个选择是使用stringi:

library(dplyr)
testitem %>%
filter(stringi::stri_endswith_fixed(areaname, "MSA"))

areaname Employment
1   Albany NY MSA        100
2   Albany GA MSA        104
3     Reno NV MSA        112
4 Syracuse NY MSA         88

或者您可以使用grepl:

library(dplyr)
testitem %>%
filter(grepl("MSA$", areaname))

或使用endsWith:

testitem %>%
filter(endsWith(areaname, "MSA"))