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带子组的组的编号后向引用

pcre regex r

Tyler Rinker DaniM · 技术社区 · 7 年前

gsub(
    "(((s?he( i|')s)|((you|they|we)( a|')re)|(I( a|')m)).{1,20})(\\b[Ff]an)(s?\\b)", 
    '\\1\\2atic\\3', 
    'He\'s the bigest fan I know.', 
    perl = TRUE, ignore.case = TRUE
)

## [1] "He's the bigest He'saticHe's I know."

(stuff before fan)(fan)(s\\b) 在伪代码中。

我知道我的正则表达式可以替换所有的组,我知道它是有效的。只是反向参考部分。

gsub(
    "(((s?he( i|')s)|((you|they|we)( a|')re)|(I( a|')m)).{1,20})(\\b[Ff]an)(s?\\b)", 
    '', 
    'He\'s the bigest fan I know.', 
    perl = TRUE, ignore.case = TRUE
)

## [1] " I know."

## [1] "He's the bigest fanatic I know."

匹配示例

inputs <- c(
    "He's the bigest fan I know.",
    "I am a huge fan of his.",
    "I know she has lots of fans in his club",
    "I was cold and turned on the fan",
    "An air conditioner is better than 2 fans at cooling."
)


outputs <- c(
    "He's the bigest fanatic I know.",
    "I am a huge fanatic of his.",
    "I know she has lots of fanatics in his club",
    "I was cold and turned on the fan",
    "An air conditioner is better than 2 fans at cooling."
)

1 回复 | 直到 7 年前

Wiktor StribiÅ¼ew 7 年前

我知道你很难抓到过多的人。把你不感兴趣的东西变成 non-capturing 或删除那些明显多余的:

((?:s?he(?: i|')s|(?:you|they|we)(?: a|')re|I(?: a|')m).{1,20})\b(Fan)(s?)\b

看到了吗 regex demo

[Ff] 可以变成 F f 既然你在开玩笑 ignore.case=TRUE

R demo :

gsub(
    "((?:s?he(?: i|')s|(?:you|they|we)(?: a|')re|I(?: a|')m).{1,20})\\b(fan)(s?)\\b", 
    '\\1\\2atic\\3', 
    inputs, 
    perl = TRUE, ignore.case = TRUE
)

输出:

[1] "He's the bigest fanatic I know."                     
[2] "I am a huge fanatic of his."                         
[3] "I know she has lots of fans in his club"             
[4] "I was cold and turned on the fan"                    
[5] "An air conditioner is better than 2 fans at cooling."

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