Split Strings into values in long dataframe format [duplicate]

问题

This question already has answers here:

Split comma-separated strings in a column into separate rows (6 answers)

Split delimited strings in a column and insert as new rows [duplicate] (6 answers)

Closed 3 years ago.

I have a dataframe that looks like the following example df which consist of a character variable VAR.

df<-data.frame(ID = 1:2, 
               VAR = c("VAL1\r\nVAL2\r\nVAL8","VAL2\r\nVAL5"),
               stringsAsFactors = FALSE)
#     ID                  VAR
# 1    1 VAL1\r\nVAL2\r\nVAL8
# 2    2         VAL2\r\nVAL5

I would like to split the character variable by the return carriage - newline \r\n and obtain the desired dataframe below:

#    ID   VAR
# 1    1 VAL1
# 2    1 VAL2
# 3    1 VAL8
# 4    2 VAL2
# 5    2 VAL5

I wrote the code as follows, but I somehow got lost in the gather function while trying to change the format of the data frame into a long format.

library(tidyverse)
df <- df %>% 
  bind_cols(as.data.frame(str_split(df$VAR,"\r\n",simplify = TRUE))) %>%
  select(-VAR) %>%
  gather(key,value)

Please advise.

回答1:

We can do this with separate_rows

library(tidyr)
separate_rows(df, VAR, sep='\\s+')

来源：https://stackoverflow.com/questions/44922612/split-strings-into-values-in-long-dataframe-format