R: Unlist into a two columns dataframe (name, value)

Question

From a named list I want to create a two columns data.frame(), with list names appearing in the first column and list elements in the second.

I managed to

Answer 1

Converting my comments to an answer, you can use stack from base R, or melt from "reshape2":

Here's stack:

head(stack(my_list), 15)
##    values        ind
## 1       0  one_digit
## 2       1  one_digit
## 3       2  one_digit
## 4       3  one_digit
## 5       4  one_digit
## 6       5  one_digit
## 7       6  one_digit
## 8       7  one_digit
## 9       8  one_digit
## 10      9  one_digit
## 11     10 two_digits
## 12     11 two_digits
## 13     12 two_digits
## 14     13 two_digits
## 15     14 two_digits

Here's melt:

head(melt(my_list), 15)
##    value         L1
## 1      0  one_digit
## 2      1  one_digit
## 3      2  one_digit
## 4      3  one_digit
## 5      4  one_digit
## 6      5  one_digit
## 7      6  one_digit
## 8      7  one_digit
## 9      8  one_digit
## 10     9  one_digit
## 11    10 two_digits
## 12    11 two_digits
## 13    12 two_digits
## 14    13 two_digits
## 15    14 two_digits

One difference between the two approaches is that melt will automatically create the "L1" column even if the list doesn't have names, and will work with nested lists too.

head(melt(unname(my_list)), 15)
##    value L1
## 1      0  1
## 2      1  1
## 3      2  1
## 4      3  1
## 5      4  1
## 6      5  1
## 7      6  1
## 8      7  1
## 9      8  1
## 10     9  1
## 11    10  2
## 12    11  2
## 13    12  2
## 14    13  2
## 15    14  2