r - 字符串中格式错误的字符串

Question

我有一个简单的字符串:

y <- "Location 433900E 387200N, Lat 53.381 Lon -1.490, 131 metres amsl"

当我对其执行正则表达式捕获时:

stringr::str_extract(r'Lat(.*?)\,', y)

我收到此错误:

>Error: malformed raw string literal at line 1

为什么？

Answer 1

使用 R 的原始字符串(在版本 4.0.0 中引入)，您需要使用 ( 或 [ 或 { 以及引号，例如，

r'{Lat(.*?)\,}'

这记录在?Quotes(以及发行说明中):

Raw character constants are also available using a syntax similar to the one used in C++: r"(...)" with ... any character sequence, except that it must not contain the closing sequence )"⁠. The delimiter pairs [] and {} can also be used, and R can be used in place of r."