extract content of large lists through a loop - r

Question

i have about 30 padronized large list and i want to extract elements that are organized in the same way in all of them.
> df[[2]][[1]][[4]][[1]][[1]][[1]][[1]][[3]][[1]]
[1] "Non-histaminic angioedema"
> df[[2]][[1]][[4]][[1]][[1]][[2]][[1]][[3]][[1]]
[1] "Rare urticaria"
> df[[2]][[1]][[4]][[1]][[1]][[3]][[1]][[3]][[1]]
[1] "Rare allergic respiratory disease"
i want a loop to extract all these info to a data.frame. I tried to use lapply, but i'm having trouble with the right function to use.
i never used the apply family, so i would be very grateful with some tips
-----------------edit
str(df)
$ Availability:List of 1
..$ Licence:List of 3
.. ..$ FullName :List of 2
.. .. ..$ text : chr "Creative Commons Attribution 4.0 International"
.. .. ..$ .attrs: Named chr "en"
.. .. .. ..- attr(*, "names")= chr "lang"
.. ..$ ShortIdentifier: chr "CC-BY-4.0"
.. ..$ LegalCode : chr "https://creativecommons.org/licenses/by/4.0/legalcode"
$ DisorderList:List of 2
..$ Disorder:List of 5
.. ..$ OrphaNumber : chr "98050"
.. ..$ ExpertLink :List of 2
.. .. ..$ text : chr "http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=98050"
.. .. ..$ .attrs: Named chr "en"
.. .. .. ..- attr(*, "names")= chr "lang"
.. ..$ Name :List of 2
.. .. ..$ text : chr "Rare allergic disease"
.. .. ..$ .attrs: Named chr "en"
.. .. .. ..- attr(*, "names")= chr "lang"
.. ..$ ClassificationNodeList:List of 2
.. .. ..$ ClassificationNode:List of 1
.. .. .. ..$ ClassificationNodeChildList:List of 5
.. .. .. .. ..$ ClassificationNode:List of 2
.. .. .. .. .. ..$ Disorder :List of 4
.. .. .. .. .. .. ..$ OrphaNumber: chr "658"
.. .. .. .. .. .. ..$ ExpertLink :List of 2
.. .. .. .. .. .. .. ..$ text : chr "http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=658"
.. .. .. .. .. .. .. ..$ .attrs: Named chr "en"
.. .. .. .. .. .. .. .. ..- attr(*, "names")= chr "lang"
.. .. .. .. .. .. ..$ Name :List of 2
.. .. .. .. .. .. .. ..$ text : chr "Non-histaminic angioedema"
.. .. .. .. .. .. .. ..$ .attrs: Named chr "en"
.. .. .. .. .. .. .. .. ..- attr(*, "names")= chr "lang"
.. .. .. .. .. .. ..$ .attrs : Named chr "8618"
.. .. .. .. .. .. .. ..- attr(*, "names")= chr "id"
.. .. .. .. .. ..$ ClassificationNodeChildList:List of 3
.. .. .. .. .. .. ..$ ClassificationNode:List of 2
.. .. .. .. .. .. .. ..$ Disorder :List of 4
.. .. .. .. .. .. .. .. ..$ OrphaNumber: chr "91378"
.. .. .. .. .. .. .. .. ..$ ExpertLink :List of 2
.. .. .. .. .. .. .. .. .. ..$ text : chr "http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=91378"
.. .. .. .. .. .. .. .. .. ..$ .attrs: Named chr "en"
.. .. .. .. .. .. .. .. .. .. ..- attr(*, "names")= chr "lang"
.. .. .. .. .. .. .. .. ..$ Name :List of 2
.. .. .. .. .. .. .. .. .. ..$ text : chr "Hereditary angioedema"
.. .. .. .. .. .. .. .. .. ..$ .attrs: Named chr "en"
.. .. .. .. .. .. .. .. .. .. ..- attr(*, "names")= chr "lang"
.. .. .. .. .. .. .. .. ..$ .attrs : Named chr "12136"
.. .. .. .. .. .. .. .. .. ..- attr(*, "names")= chr "id"
.. .. .. .. .. .. .. ..$ ClassificationNodeChildList:List of 3
.. .. .. .. .. .. .. .. ..$ ClassificationNode:List of 2
.. .. .. .. .. .. .. .. .. ..$ Disorder :List of 4
.. .. .. .. .. .. .. .. .. .. ..$ OrphaNumber: chr "528623"
.. .. .. .. .. .. .. .. .. .. ..$ ExpertLink :List of 2
.. .. .. .. .. .. .. .. .. .. .. ..$ text : chr "http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=528623"
this represents the structure of one of my lists, and i want to extract only what is contained in
df$DisorderList$Disorder$ClassificationNodeList$ClassificationNode$ClassificationNodeChildList$ClassificationNode$Disorder$Name$text
as you can see, this structure repeats along the file (in this case, twice, because I paste only a small part)
head(df$DisorderList$Disorder$ClassificationNodeList$ClassificationNode$ClassificationNodeChildList[1]$ClassificationNode$Disorder$Name$text)
[1] "Non-histaminic angioedema"
head(df$DisorderList$Disorder$ClassificationNodeList$ClassificationNode$ClassificationNodeChildList[2]$ClassificationNode$Disorder$Name$text)
[1] "Hereditary angioedema"
I want to extract these information in each of the 30 lists I have

Answer 1

We can use sapply to loop over the index of the 6th nested list and extract that component (assuming all other index are constant)
sapply(1:30, function(i) df[[2]][[1]][[4]][[1]][[1]][[i]][[1]][[3]][[1]])
It is better to check the length of the list to make this more dynamic
l1 <- length(df[[2]][[1]][[4]][[1]][[1]][[i]])
sapply(seq_len(l1), function(i) df[[2]][[1]][[4]][[1]][[1]][[i]][[1]][[3]][[1]])
Or if we use the OP's updated post with names
sapply(seq_len(l1), function(i)
df$DisorderList$Disorder$ClassificationNodeList$ClassificationNode$ClassificationNodeChildList[i]$ClassificationNode$Disorder$Name$text)
Using a reproducible example
lapply(1:3, function(i) df[[2]][[1]][[4]][[1]][[1]][[i]][[1]][[2]][[1]])
#[[1]]
#[1] 1 2 3
#[[2]]
#[1] 1 2 3
#[[3]]
#[1] 1 2 3
Or with pluck
library(purrr)
map(1:3, ~ pluck(df, 2, 1, 4, 1, 1, .x, 1, 2, 1))
#[[1]]
#[1] 1 2 3
#[[2]]
#[1] 1 2 3
#[[3]]
#[1] 1 2 3
data
df <- replicate(3, replicate(2, replicate(4, replicate(4, replicate(3, replicate(5, list( list( list( 1:3, 1:5), list( 1:3, 1:5))), simplify = FALSE), simplify = FALSE), simplify = FALSE), simplify = FALSE), simplify = FALSE), simplify = FALSE)