正则表达式到直到托架关闭的第一次出现

Question

我有一个名为cars串如下：

cars 
[1] "Only one car(52;model-14557) had a good engine(workable condition), others engine were damaged beyond repair" 
[2] "Other car(21, model-155) looked in good condition but car (36, model-8878) looked to be in terrible condition." 

我需要从字符串中提取以下部分：

car(52;model-14557) 
car(21, model-155) 
car (36, model-8878) 

我尝试使用下面的一块可以提取它：

stringr::str_extract_all(cars, "(.car\\s{0,5}\\(([^]]+)\\))") 

这给了我以下输出：

[[1]] 
[1] " car(52;model-14557) had a good engine(workable condition)" 

[[2]] 
[1] " car(21, model-155) looked in good condition but car (36, model-8878)" 

有没有一种方法可以提取带有关联号码和型号的单词汽车？

Answer 1

Your regex does not work因为您使用的不是]匹配(和)，因而从第一(直到最后)中间没有]匹配其他[^]]+，一个或多个符号。

使用

> cars <- c("Only one car(52;model-14557) had a good engine(workable condition), others engine were damaged beyond repair","Other car(21, model-155) looked in good condition but car (36, model-8878) looked to be in terrible condition.") 
> library(stringr) 
> str_extract_all(cars, "\\bcar\\s*\\([^()]+\\)") 
[[1]] 
[1] "car(52;model-14557)" 

[[2]] 
[1] "car(21, model-155)" "car (36, model-8878)" 

正则表达式为\bcar\s*\([^()]+\)，看到online regex demo here。

它匹配：

• \b - 字边界
• car - 字面炭序列
• \s* - 0+空格
• \( - 字面(
• [^()]+ - 1或除(和)之外的更多字符
• \) - 字面值)。

注相同的正则表达式将产生与以下基础R代码相同的结果：

> regmatches(cars, gregexpr("\\bcar\\s*\\([^()]+\\)", cars)) 
[[1]] 
[1] "car(52;model-14557)" 

[[2]] 
[1] "car(21, model-155)" "car (36, model-8878)"