如何在分隔符之前拆分字符串？

Question

我有一个如下所示的字符串。

a <- "T,2016,07,T,2016,07,22,T,2016,07"

我想把它分开来得到这个，

b <- c("T,2016,07", "T,2016,07", "T,2016,07")

你可以告诉我这个方法吗？非常感谢。

Answer 1

或使用正则表达式进行拆分：

strsplit(a, ",(?=T)", perl = T)
# [[1]]
# [1] "T,2016,07"    "T,2016,07,22" "T,2016,07"

Answer 2

你可以做到

x <- gsub("T", "%T", a)
y <- unlist(strsplit(x, "%"))[-1]

Answer 3

a <- "T,2016,07,T,2016,07,22,T,2016,07"
paste0("T", Filter(nzchar, strsplit(a, ",?T")[[1]]))
# [1] "T,2016,07"    "T,2016,07,22" "T,2016,07"