Convert Mixed-Length named List to data.frame

Question

I have a list of the following format:

[[1]]
[[1]]$a
[1] 1

[[1]]$b
[1] 3

[[1]]$c
[1] 5

[[2]]       
[[2]]$c
[1] 2

[[2]]$a
[1] 3

There i

Answer 1

I know this is an old question, but I just came across it and it's excruciating not to see the simplest solution I'm aware of. So here it is (simply specify 'fill=TRUE' in rbindlist):

library(data.table)
list = list(list(a=1,b=3,c=5),list(c=2,a=3))
rbindlist(list,fill=TRUE)

#    a  b c
# 1: 1  3 5
# 2: 3 NA 2

I don't know if this is the fastest way, but I'd be willing to bet that it competes, given data.table's thoughtful design and extremely good performance on a lot of other tasks.