从字符串提取创建多列

Question

所以我有一个文本要从中提取。这是我的文字：

Charge: Larceny; Charge: Stealing a motor vehicle;

我正在尝试创建这个

Charge1     Charge2                        Charge3
Larceny     Stealing a motor vehicle       NA

有什么想法吗？现在我的代码是这样的：

data$charge <- str_extract_all(data, "(?=Charge:)(\D){4,100}")

但它只创建了一列。请帮忙！

Answer 1

如果您的文本都是相同的格式，那么使用tidyverse:将非常容易

require(tidyverse)
df <- data.frame(text = c("Charge: Larceny; Charge: Stealing a motor vehicle;", 
"Charge: some_charge; Charge: another_charge; Charge: something_else"))
df %>% separate(text, c("Charge1", "Charge2", "Charge3"), sep = "; Charge: ") %>%
mutate(Charge1 = gsub("Charge: ", "", Charge1))

您可能需要通过清除一些挂起的分号

Answer 2

我们可以使用tidyverse来完成这个

library(tidyerse)
tibble(str1) %>%
separate_rows(str1, sep= ";\s*") %>%
separate(str1, into = c("col1", "col2"), sep=":\s*") %>% 
mutate(col1 = na_if(col1, "")) %>% 
fill(col1) %>%
mutate(col1 = paste0(col1, row_number())) %>%
spread(col1, col2)
# A tibble: 1 x 3
# Charge1 Charge2                  Charge3
#  <chr>   <chr>                    <chr>  
#1 Larceny Stealing a motor vehicle NA     

数据

str1 <- "Charge: Larceny; Charge: Stealing a motor vehicle;"

Answer 3

使用基R:

read.table(text=gsub("\s*Charge:\s*","",strng),sep=";",fill=T,col.names = paste0("Charge",1:3))
Charge1                  Charge2 Charge3
1 Larceny Stealing a motor vehicle      NA

您也可以使用strcapture。但不如gsub:灵活

strcapture(paste0(rep("\s*Charge:\s*([^;]+);",2),collapse=""),strng,data.frame(charge1=character(),charge2=character()))
charge1                  charge2
1 Larceny Stealing a motor vehicle

Answer 4

稍微修改您的解决方案。注意?=和?<=之间的差异(先行和后向(以及\D与;匹配。

str_extract_all(data, "(?<=Charge: )[^;]+")
[[1]]
[1] "Larceny"                  "Stealing a motor vehicle"

所以str_extract_all((将返回一个向量列表，如何将它们放入数据中。框架可以在StackOverflow的其他角落看到。