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想text在句子中拆分字符元素的向量。拆分标准的模式不止一种 ( "and/ERT", "/$")。模式中也有例外（:/$., and/ERT then, ./$. Smiley）。

尝试：匹配应该拆分的情况。"^&*"在那个地方插入一个不寻常的图案 ( )。strsplit具体模式

问题：我不知道如何正确处理异常。在某些明确的情况下，"^&*"应该消除异常模式 ()，并在运行之前恢复原始文本strsplit。

代码：

text <- c("This are faulty propositions one and/ERT two ,/$, which I want to split ./$. There are cases where I explicitly want and/ERT some where I don't want to split ./$. For example :/$. when there is an and/ERT then I don't want to split ./$. This is also one case where I dont't want to split ./$. Smiley !/$. Thank you ./$!",
"This are the same faulty propositions one and/ERT two ,/$, which I want to split ./$. There are cases where I explicitly want and/ERT some where I don't want to split ./$. For example :/$. when there is an and/ERT then I don't want to split ./$. This is also one case where I dont't want to split ./$. Smiley !/$. Thank you ./$!",
"Like above the same faulty propositions one and/ERT two ,/$, which I want to split ./$. There are cases where I explicitly want and/ERT some where I don't want to split ./$. For example :/$. when there is an and/ERT then I don't want to split ./$. This is also one case where I dont't want to split ./$. Smiley !/$. Thank you ./$!")

patternSplit <- c("and/ERT", "/\\$") # The class of split-cases is much larger then in this example. Therefore it is not possible to adress them explicitly.
patternSplit <- paste("(", paste(patternSplit, collapse = "|"), ")", sep = "")

exceptionsSplit <- c("\\:/\\$\\.", "and/ERT then", "\\./\\$\\. Smiley")
exceptionsSplit <- paste("(", paste(exceptionsSplit, collapse = "|"), ")", sep = "")

# If you don't have exceptions, it works here. Unfortunately it splits "*$/*" into "*" and "$/*". Would be convenient to avoid this. See example "ideal" split below.
textsplitted <- strsplit(gsub(patternSplit, "^&*\\1", text), "^&*", fixed = TRUE) # 

# Ideal split:
textsplitted
> textsplitted
[[1]]
 [1] "This are faulty propositions one and/ERT" 
 [2] "two ,/$," 
 [3] "which I want to split ./$."
 [4] "There are cases where I explicitly want and/ERT" 
 [5] "some where I don't want to split ./$." 
 [6] "For example :/$. when there is an and/ERT then I don't want to split ./$."
 [7] "This is also one case where I dont't want to split ./$. Smiley !/$." 
 [8] "Thank you ./$!"

[[2]]
 [1] "This are the same faulty propositions one and/ERT 
 [2] "two ,/$,"
#...      

# This try doesen't work!
text <- gsub(patternSplit, "^&*\\1", text)
text <- gsub(exceptionsSplit, "[original text without "^&*"]", text)
textsplitted <- strsplit(text, "^&*", fixed = TRUE)
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1 回答 1

9

我认为您可以使用此表达式来获得所需的拆分。当strsplit用完它拆分的字符时，您将不得不在匹配/不匹配的内容后面的空格上拆分（这是您在 OP 中所需的输出中所拥有的）：

strsplit( text[[1]] , "(?<=and/ERT)\\s(?!then)|(?<=/\\$[[:punct:]])(?<!:/\\$[[:punct:]])\\s(?!Smiley)"  , perl = TRUE )
#[[1]]
#[1] "This are faulty propositions one and/ERT"                                 
#[2] "two ,/$,"                                                                 
#[3] "which I want to split ./$."                                               
#[4] "There are cases where I explicitly want and/ERT"                          
#[5] "some where I don't want to split ./$."                                    
#[6] "For example :/$. when there is an and/ERT then I don't want to split ./$."
#[7] "This is also one case where I dont't want to split ./$. Smiley !/$."      
#[8] "Thank you ./$!"

解释

  • (?<=and/ERT)\\s\\s- 在一个空间上 分割，前面是，(?<=...)由"and/ERT"
  • (?!then) - 但只有在那个空格后面没有(?!...)，由"then"
  • | - OR 运算符链接下一个表达式
  • (?<=/\\$[[:punct:]])"/$"-后跟任何标点符号的 正面后向断言
  • (?<!:/\\$[[:punct:]])\\s(?!Smiley)- 匹配一个前面没有的空格（但根据上一点IS前面但NOT后面，由":/$"[[:punct:]]"/$[[:punct:]]"(?!...)"Smiley"
于 2013-09-09T12:55:06.913 回答