英文:
Keep the last n columns only outputted by separate by delimiter
问题
我有一个包含以下因子变量的数据框：
> head(example.df)path1 C:/Users/My PC/pinkhipppos/tinyhorsefeet/location1/categoryA/eyoshdzjow_random_image.txt
（虚构的目录）。
我想根据分隔符 / 拆分成单独的列。
我可以使用以下代码实现：
library(tidyverse)example.df <- example.df %>%separate(path,into=c("dir","ok","hello","etc...","finally...","location","category","filename"),sep="/")
尽管如此，我只关心最后两个目录和文件名，或来自分隔函数的最后 3 个结果。因为父目录（高于 location 的部分）可能会更改。我期望的输出如下：
> head(example.df)location category filename1 location1 categoryA eyoshdzjow_random_image.txt
可复制的示例：
example.df <- as.data.frame(c("C:/Users/My PC/pinkhipppos/tinyhorsefeet/location1/categoryA/eyoshdzjow_random_image.txt","C:/Users/My PC/pinkhipppos/tinyhorsefeet/location2/categoryB/jdugnbtudg_random_image.txt"))colnames(example.df)<-"path"
英文:
I have a dataframe with the following factor variable:
> head(example.df)path1 C:/Users/My PC/pinkhipppos/tinyhorsefeet/location1/categoryA/eyoshdzjow_random_image.txt
(made up dirs).
I want to split into separate columns based on a delimiter: /.
I can do this using
library(tidyverse)example.df <- example.df %>%separate(path,into=c("dir","ok","hello","etc...","finally...","location","category","filename"),sep="/")
Although, I am only interested in the last two dirs and the file name or the last 3 results from the separate function. As parent directories (higher than location) may change. My desired output would be:
> head(example.df)location category filename1 location1 categoryA eyoshdzjow_random_image.txt
Reproducible:
example.df <- as.data.frame(c("C:/Users/My PC/pinkhipppos/tinyhorsefeet/location1/categoryA/eyoshdzjow_random_image.txt","C:/Users/My PC/pinkhipppos/tinyhorsefeet/location2/categoryB/jdugnbtudg_random_image.txt"))colnames(example.df)<-"path"
答案1
得分: 2
One way in base R is to split string at "/" and select last 3 elements from each list.
as.data.frame(t(sapply(strsplit(as.character(example.df$path), "/"), tail, 3)))
Using tidyverse, we can get the data in long format, select last 3 entries in each row, and get the data in wide format.
library(tidyverse)example.df %>%mutate(row = row_number()) %>%separate_rows(path, sep = "/") %>%group_by(row) %>%slice((n() - 2) : n()) %>%mutate(cols = c('location', 'category', 'filename')) %>%pivot_wider(names_from = cols, values_from = path) %>%ungroup() %>%select(-row)
Or a similar concept as base R but using tidyverse.
example.df %>%mutate(temp = map(str_split(path, "/"), tail, 3)) %>%unnest_wider(temp, names_repair = ~paste0("dir", seq_along(.) - 1)) %>%select(-dir0)
英文:
One way in base R is to split string at "/" and select last 3 elements from each list.
as.data.frame(t(sapply(strsplit(as.character(example.df$path), "/"), tail, 3)))# V1 V2 V3#1 location1 categoryA eyoshdzjow_random_image.txt#2 location2 categoryB jdugnbtudg_random_image.txt
Using tidyverse, we can get the data in long format, select last 3 entries in each row and get the data in wide format.
library(tidyverse)example.df %>%mutate(row = row_number()) %>%separate_rows(path, sep = "/") %>%group_by(row) %>%slice((n() - 2) : n()) %>%mutate(cols = c('location', 'category', 'filename')) %>%pivot_wider(names_from = cols, values_from = path) %>%ungroup() %>%select(-row)# A tibble: 2 x 3# location category filename# <chr> <chr> <chr>#1 location1 categoryA eyoshdzjow_random_image.txt#2 location2 categoryB jdugnbtudg_random_image.txt
Or similar concept as base R but using tidyverse
example.df %>%mutate(temp = map(str_split(path, "/"), tail, 3)) %>%unnest_wider(temp, names_repair = ~paste0("dir", seq_along(.) - 1)) %>%select(-dir0)
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