How can I make a list of lists in R? - r

Question

I don't know how to make a list of lists in R.
I have several lists, I want to store them in one data structure to make accessing them easier. However, it looks like you cannot use a list of lists in R, so if I get list l1 from another list, say, l2 then I cannot access elements l1. How can I implement it?
EDIT- I will show an example of what does not work for me:
list1 <- list()
list1[1] = 1
list1[2] = 2
list2 <- list()
list2[1] = 'a'
list2[2] = 'b'
list_all <- list(list1, list2)
a = list_all[1]
a[2]
#[[1]]
#NULL
but a should be a list!

Answer 1

You can easily make lists of lists
list1 <- list(a = 2, b = 3)
list2 <- list(c = "a", d = "b")
mylist <- list(list1, list2)
mylist is now a list that contains two lists. To access list1 you can use mylist[[1]]. If you want to be able to something like mylist$list1 then you need to do somethingl like
mylist <- list(list1 = list1, list2 = list2)
# Now you can do the following
mylist$list1
Edit: To reply to your edit. Just use double bracket indexing
a <- list_all[[1]]
a[[1]]
#[1] 1
a[[2]]
#[1] 2

Answer 2

Using your example::
list1 <- list()
list1[1] = 1
list1[2] = 2
list2 <- list()
list2[1] = 'a'
list2[2] = 'b'
list_all <- list(list1, list2)
Use '[[' to retrieve an element of a list:
b = list_all[[1]]
b
[[1]]
[1] 1
[[2]]
[1] 2
class(b)
[1] "list"

Answer 3

If you are trying to keep a list of lists (similar to python's list.append()) then this might work:
a <- list(1,2,3)
b <- list(4,5,6)
c <- append(list(a), list(b))
> c
[[1]]
[[1]][[1]]
[1] 1
[[1]][[2]]
[1] 2
[[1]][[3]]
[1] 3
[[2]]
[[2]][[1]]
[1] 4
[[2]][[2]]
[1] 5
[[2]][[3]]
[1] 6

Answer 4

The example creates a list of named lists in a loop.
MyList <- list()
for (aName in c("name1", "name2")){
MyList[[aName]] <- list(aName)
}
MyList[["name1"]]
MyList[["name2"]]
To add another list named "name3" do write:
MyList$name3 <- list(1, 2, 3)

Answer 5

As other answers pointed out in a more complicated way already, you did already create a list of lists! It's just the odd output of R that confuses (everybody?). Try this:
> str(list_all)
List of 2
$ :List of 2
..$ : num 1
..$ : num 2
$ :List of 2
..$ : chr "a"
..$ : chr "b"
And the most simple construction would be this:
> str(list(list(1, 2), list("a", "b")))
List of 2
$ :List of 2
..$ : num 1
..$ : num 2
$ :List of 2
..$ : chr "a"
..$ : chr "b"