拆分一个字符串，其中大写字母在 stringr 中跟随小写字母

Question

我有一个看起来像这样的字符串向量，我想将它拆分：

str <- c("Fruit LoopsJalapeno Sandwich", "Red Bagel", "Basil LeafBarbeque SauceFried Beef")

str_split(str, '[a-z][A-Z]', n = 3)

[[1]]
[1] "Fruit Loop"       "alapeno Sandwich"

[[2]]
[1] "Red Bagel"

[[3]]
[1] "Basil Lea"    "arbeque Sauc" "ried Beef"

但我需要将这些字母保留在单词的末尾和开头。

Answer 1

这是基本的 2 种方法（如果需要，您可以概括为 stringr）。

这个用一个占位符代替这个地方，然后拆分那个。

strsplit(gsub("([a-z])([A-Z])", "\1SPLITHERE\2", str), "SPLITHERE")

## [[1]]
## [1] "Fruit Loops"       "Jalapeno Sandwich"
## 
## [[2]]
## [1] "Red Bagel"
## 
## [[3]]
## [1] "Basil Leaf"     "Barbeque Sauce" "Fried Beef"

此方法使用先行和后行：

strsplit(str, "(?<=[a-z])(?=[A-Z])", perl=TRUE)

## [[1]]
## [1] "Fruit Loops"       "Jalapeno Sandwich"
## 
## [[2]]
## [1] "Red Bagel"
## 
## [[3]]
## [1] "Basil Leaf"     "Barbeque Sauce" "Fried Beef"

EDIT 泛化为 stringr 所以如果你想要可以抓取 3 个

stringr::str_split(gsub("([a-z])([A-Z])", "\1SPLITHERE\2", str), "SPLITHERE", 3)

Answer 2

您也可以根据您的字符串匹配而不是 splitting。

unlist(regmatches(str, gregexpr('[A-Z][a-z]+ [A-Z][a-z]+', str)))
# [1] "Fruit Loops"       "Jalapeno Sandwich" "Red Bagel"        
# [4] "Basil Leaf"        "Barbeque Sauce"    "Fried Beef"

拆分一个字符串，其中大写字母在 stringr 中跟随小写字母

splitting a string in which upper case follows lower case in stringr

regex

r

stringr