多个组的正则表达式

Question

文本挖掘新手尝试提取各种字符并更新列。我尝试过使用 str_extract 但似乎无法处理正则表达式语法。有人可以告诉我吗？谢谢!

可重复的数据

data.frame("name" = c("D1. Hi my name", "A3.3. Hello this is"), "Amount" = c(1, 4))

        name            Amount
1     D1. Hi my name      1
2 A3.3. Hello this is     4

预期输出

        name           Amount New Name       Extracted
1     D1. Hi my name      1     Hi my name      D1.
2 A3.3. Hello this is     4    Hello this is    A3.3.

Answer 1

我们可以使用 tidyr 中的extract。在这里，我们通过匹配不是空格(\\S+)后跟空格的模式来捕获并捕获第二组字符

library(tidyverse)
df2 %>% 
    extract(name, into = c("Extracted", "NewName"), "^(\\S+) (.*)", 
             remove = FALSE) %>%
     select(names(df1),NewName, Extracted)
#               name Amount       NewName Extracted
#1      D1. Hi my name      1    Hi my name       D1.
#2 A3.3. Hello this is      4 Hello this is     A3.3.

---

或者使用base R，我们可以使用sub创建分隔符，然后使用read.csv

cbind(df2, read.csv(text = sub("\\s", ",", df2$name), 
           header = FALSE, col.names = c("Extracted", "NewName")))