在数据帧

Question

应用str_split的专栏中，我有以下DF名为I：

structure(list(price = c(11772, 14790, 2990, 1499, 21980, 27999 
), fuel = c("diesel", "petrol", "petrol", "diesel", "diesel", 
"petrol"), gearbox = c("manual", "manual", "manual", "manual", 
"automatic", "manual"), colour = c("white", "purple", "yellow", 
"silver", "red", "rising blue metalli"), engine_size = c(1685, 
1199, 998, 1753, 2179, 1984), mileage = c(18839, 7649, 45058, 
126000, 31891, 100), year = c("2013 hyundai ix35", "2016 citroen citroen ds3 cabrio", 
"2007 peugeot 107 hatchback", "2007 ford ford focus hatchback", "2012 jaguar xf saloon", 
"2016 volkswagen scirocco coupe"), doors = c(5, 2, 3, 5, 4, 3 
)), .Names = c("price", "fuel", "gearbox", "colour", "engine_size", 
"mileage", "year", "doors"), row.names = c(NA, 6L), class = "data.frame") 

一些“年”列中的字被复制。我想删除它们。作为第一步，我想用单独的单词分隔此列中的字符串。 我能做到这一点单独的字符串，但是当我尝试将其应用到整个数据帧它给出了一个错误

unlist(str_split("2013 hyunday ix35", "[[:blank:]]")) 

[1]“2013”​​“hyunday”，“ix35的”

for(k in 1:nrow(i)) 
+ i[k,7]<-unlist(str_split(i[k, 7], "[[:blank:]]")) 

错误[<-.data.frame（*tmp*，K，7，值= C（ “2013”​​， “现代”，： 更换已3行，数据具有1

Answer 1

我们可以通过一个或多个空间分开（\\s+ ）和paste th Ëunique元素结合在一起通过的list输出（sapply(..）

i$year <- sapply(strsplit(i$year, "\\s+"), function(x) paste(unique(x), collapse=' ')) 

Answer 2

与dplyr和stringr工作（与purrr帮助与列表工作）循环，你可以这样做：

library(dplyr) 
df %>% 
    mutate(newyear = purrr::map_chr(
    stringr::str_split(year, pattern = "[[:blank:]]"), 
    ~ paste(unique(.x), collapse = " ") 
    )) 
#> price fuel gearbox    colour engine_size mileage 
#> 1 11772 diesel manual    white  1685 18839 
#> 2 14790 petrol manual    purple  1199 7649 
#> 3 2990 petrol manual    yellow   998 45058 
#> 4 1499 diesel manual    silver  1753 126000 
#> 5 21980 diesel automatic     red  2179 31891 
#> 6 27999 petrol manual rising blue metalli  1984  100 
#>        year doors      newyear 
#> 1    2013 hyundai ix35  5    2013 hyundai ix35 
#> 2 2016 citroen citroen ds3 cabrio  2  2016 citroen ds3 cabrio 
#> 3  2007 peugeot 107 hatchback  3  2007 peugeot 107 hatchback 
#> 4 2007 ford ford focus hatchback  5  2007 ford focus hatchback 
#> 5   2012 jaguar xf saloon  4   2012 jaguar xf saloon 
#> 6 2016 volkswagen scirocco coupe  3 2016 volkswagen scirocco coupe