Combining unequal lists into data.frame object based on its variable name

user_12327305 0
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Pretty trivial task but couldn't find the answer and struggling with getting proper solution.

I want to combine lots of different variables(lists) containing unequal amount of string data into single data.frame object where first column gets the variable name and second it's assigned values.

E.g.
Variable_1

         name
1    actor_id
2  first_name
3   last_name
4 last_update

Variable_2

         name
1  address_id
2     address
3    address2
4    district
5     city_id
6 postal_code
7       phone
8 last_update

Expectd output:

1 Variable_1 actor_id
2 Variable_1 first_name
3 Variable_1 last_name
4 Variable_1 last_update
5 Variable_2 address_id
6 Variable_2 address
7 Variable_2 address2
8 Variable_2 district
9 Variable_2 city_id
10 Variable_2 postal_code
11 Variable_2 phone
12 Variable_2 last_update

i bet there must be multiple aproaches. thanks for the tips in advance!

dplyr dataframe r list
2 Answers

Assuming the list object is named, create a new column from the names and rbind the list elements with do.call

out <- do.call(rbind, Map(cbind, varname = names(lst1), lst1))
row.names(out) <- NULL

Or we may use bind_rows

library(purrr)
library(dplyr)
bind_rows(lst1, .id = 'varname') %>%
     as_tibble

data

lst1 <- list(Variable_1 = structure(list(name = c("actor_id", "first_name", 
"last_name", "last_update")), class = "data.frame", row.names = c("1", 
"2", "3", "4")), Variable_2 = structure(list(name = c("address_id", 
"address", "address2", "district", "city_id", "postal_code", 
"phone", "last_update")), class = "data.frame", row.names = c("1", 
"2", "3", "4", "5", "6", "7", "8")))
user_37322710

Example data

variable1 <- paste0("variable1_",1:2)
variable2 <- paste0("variable2_",1:3)

How to

expand.grid(variable1,variable2)

Result

         Var1        Var2
1 variable1_1 variable2_1
2 variable1_2 variable2_1
3 variable1_1 variable2_2
4 variable1_2 variable2_2
5 variable1_1 variable2_3
6 variable1_2 variable2_3
user_96960370
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