Unnest one column list to many columns in tidyr

问题

For example, I have a tidy data frame like this:

df <- tibble(id=1:2,
         ctn=list(list(a="x",b=1),
                  list(a="y",b=2)))
# A tibble: 2 x 2
     id        ctn
  <int>     <list>
1     1 <list [2]>
2     2 <list [2]>

How could I unnest ctn column to the right so that the data frame will be like this:

# A tibble: 2 x 3
     id     a     b
  <int> <chr> <dbl>
1     1     x     1
2     2     y     2

回答1:

With dplyr and purrr

df %>% 
  mutate(ctn = map(ctn, as_tibble)) %>%
  unnest()

# A tibble: 2 x 3
     id     a     b
  <int> <chr> <dbl>
1     1     x     1
2     2     y     2

回答2:

One option is

library(data.table)
setDT(df)[, unlist(ctn, recursive = FALSE), id]
#   id a b
#1:  1 x 1
#2:  2 y 2

---

Or with tidyr

library(tidyverse)
df$ctn %>%
     setNames(., df$id) %>%
     bind_rows(., .id = 'id')
# A tibble: 2 x 3
#   id     a     b
#  <chr> <chr> <dbl>
#1     1     x     1
#2     2     y     2

来源：https://stackoverflow.com/questions/45328221/unnest-one-column-list-to-many-columns-in-tidyr