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Regex 多个重叠正则表达式匹配,而不是一个_Regex_R - Fatal编程技术网

Regex 多个重叠正则表达式匹配,而不是一个

Regex 多个重叠正则表达式匹配,而不是一个,regex,r,Regex,R,考虑以下字符串: data <- "1-FA-1-I2-1-I2-1-I2-1-EX-1-I2-1-I3-1-FA-1-I1-1-I2-1-TR-1-I1-1-I2-1-FA-1-I3-1-I1-1-FA-1-FA-1-NR-1-I3-1-I2-1-TR-1-I1-1-I2-1-I1-1-I2-1-FA-1-I2-1-I1-1-I3-1-FA-1-QU-1-I1-1-I2-1-I2-1-I2-1-NR-1-I2-1-I2-1-NR-1-I1-1-I2-1-I1-1-NR-1-I3-1-QU

考虑以下字符串:

data <- "1-FA-1-I2-1-I2-1-I2-1-EX-1-I2-1-I3-1-FA-1-I1-1-I2-1-TR-1-I1-1-I2-1-FA-1-I3-1-I1-1-FA-1-FA-1-NR-1-I3-1-I2-1-TR-1-I1-1-I2-1-I1-1-I2-1-FA-1-I2-1-I1-1-I3-1-FA-1-QU-1-I1-1-I2-1-I2-1-I2-1-NR-1-I2-1-I2-1-NR-1-I1-1-I2-1-I1-1-NR-1-I3-1-QU-1-I2-1-I3-1-QU-1-NR-1-I2-1-I1-1-NR-1-QU-1-QU-1-I2-1-I1-1-EX"
这将匹配第一个
I3
和最后一个
I3
之间的部分。但是,我应该如何修改正则表达式以匹配以
I3开始和结束的每个单独部分?例如

I3-1-FA-1-I1-1-I2-1-TR-1-I1-1-I2-1-FA-1-I3
I3-1-I1-1-FA-1-FA-1-NR-1-I3
I3-1-I2-1-TR-1-I1-1-I2-1-I1-1-I2-1-FA-1-I2-1-I1-1-I3
I3-1-FA-1-QU-1-I1-1-I2-1-I2-1-I2-1-NR-1-I2-1-I2-1-NR-1-I1-1-I2-1-I1-1-NR-1-I3
I3-1-QU-1-I2-1-I3

使用非贪婪形式和积极的前瞻

"(?=(I3.+?I3))"
从组索引1中获取所需的字符串。Lookaheads有助于进行重叠匹配。在
R
中,必须启用
perl=TRUE
参数


您可以将
strsplit
gsub
一起使用,如下所示:

data <- "1-FA-1-I2-1-I2-1-I2-1-EX-1-I2-1-I3-1-FA-1-I1-1-I2-1-TR-1-I1-1-I2-1-FA-1-I3-1-I1-1-FA-1-FA-1-NR-1-I3-1-I2-1-TR-1-I1-1-I2-1-I1-1-I2-1-FA-1-I2-1-I1-1-I3-1-FA-1-QU-1-I1-1-I2-1-I2-1-I2-1-NR-1-I2-1-I2-1-NR-1-I1-1-I2-1-I1-1-NR-1-I3-1-QU-1-I2-1-I3-1-QU-1-NR-1-I2-1-I1-1-NR-1-QU-1-QU-1-I2-1-I1-1-EX"
data <- gsub(".*?(I3.*?)(?=I3)","\\1I3§",data,perl=T)
strsplit(gsub("[^§]*$", "", data),"§")

/I3.+?I3/
,也许?@Biffen:这会得到1/2的必要匹配,但由于它使用第一个匹配的最后一个
I3
作为该匹配的端点,它无法得到第二个和第三个
I3
之间的第二个延伸,而是直接跳到第三个必需的匹配。啊,好的一点。正如其中一个答案中所建议的那样,环顾四周就可以了。在
R
data <- "1-FA-1-I2-1-I2-1-I2-1-EX-1-I2-1-I3-1-FA-1-I1-1-I2-1-TR-1-I1-1-I2-1-FA-1-I3-1-I1-1-FA-1-FA-1-NR-1-I3-1-I2-1-TR-1-I1-1-I2-1-I1-1-I2-1-FA-1-I2-1-I1-1-I3-1-FA-1-QU-1-I1-1-I2-1-I2-1-I2-1-NR-1-I2-1-I2-1-NR-1-I1-1-I2-1-I1-1-NR-1-I3-1-QU-1-I2-1-I3-1-QU-1-NR-1-I2-1-I1-1-NR-1-QU-1-QU-1-I2-1-I1-1-EX"
data <- gsub(".*?(I3.*?)(?=I3)","\\1I3§",data,perl=T)
strsplit(gsub("[^§]*$", "", data),"§")
[1] "I3-1-FA-1-I1-1-I2-1-TR-1-I1-1-I2-1-FA-1-I3"                                   
[2] "I3-1-I1-1-FA-1-FA-1-NR-1-I3"                                                  
[3] "I3-1-I2-1-TR-1-I1-1-I2-1-I1-1-I2-1-FA-1-I2-1-I1-1-I3"                         
[4] "I3-1-FA-1-QU-1-I1-1-I2-1-I2-1-I2-1-NR-1-I2-1-I2-1-NR-1-I1-1-I2-1-I1-1-NR-1-I3"
[5] "I3-1-QU-1-I2-1-I3"