R：使用strsplit和perl REGEX語法提取大寫字母和特殊字符

Question

如何僅提取帶有以下大寫字母的/以及整個[[:punct:]]/$[[:punct:]] 。

text <- c("This/ART ,/$; Is/NN something something/else A/VAFIN faulty/ADV text/ADV which/ADJD i/PWS propose/ADV as/APPR Example/NE ./$. So/NE It/PTKNEG makes/ADJD no/VAFIN sense/ADV at/KOUS all/PDAT ,/$, it/APPR Has/ADJA Errors/NN  ,/$; and/APPR it/APPR is/CARD senseless/NN again/ART ./$:")

# HOW to?
textPOS <- strsplit(text,"(   )|(?<=[[:punct:]]/\\$[[:punct:]])", perl=TRUE)
#                          ^^^ 
#                         extract only the "/" with the following capital letters
#                         and the whole "[[:punct:]]/$[[:punct:]]"

# Expected RETURN:
> textPOS
[1] "/ART" ",/$;" "/NN" "/VAFIN" "/ADV" "/ADV" "/ADJD" "/PWS" "/ADV" "/APPR" "/NE" "./$." "/NE" "/PTKNEG" "/ADJD" "/VAFIN" "/ADV" "/KOUS" "/PDAT" ",/$," "/APPR" "/ADJA" "/NN" ",/$;" "/APPR" "/APPR" "/CARD" "/NN" "/ART" "./$:"

謝謝！ :)

Answer 1

您可以使用gregexpr和regmatches ：

regmatches(text, gregexpr('[[:punct:]]*/[[:alpha:][:punct:]]*', text))
# [[1]]
#  [1] "/ART"    "/NN"     "/VAFIN"  "/ADV"    "/ADV"    "/ADJD"   "/PWS"    "/ADV"    "/APPR"   "/NE"     "./$."    "/NE"    
# [13] "/PTKNEG" "/ADJD"   "/VAFIN"  "/ADV"    "/KOUS"   "/PDAT"   ",/$,"    "/APPR"   "/ADJA"   "/NN"     ",/$;"    "/APPR"  
# [25] "/APPR"   "/CARD"   "/NN"     "/ART"    "./$:"   

正則表達式用詞來表達：“查找以零個或多個標點符號開頭，后跟一個斜杠，一個或多個字母或標點符號的東西。如果要包含數字，請切換到[:alnum:] 。

---

根據注釋，如果只需要大寫字母，則正則表達式將變為：

regmatches(text, gregexpr('[[:punct:]]*/[[:upper:][:punct:]]*', text))

正如@eddi所建議的， [AZ]和[:upper:]大致相等。 再次如@eddi所示，此正則表達式將捕獲/ LETTERS以及/ $ punct的情況：

/[A-Z]+|[[:punct:]]/\\$[[:punct:]]