How to perform selective rbind on datasets in R - r

Question

I am trying to use rbind to append different datasets countrywise. The list of the datasets is
data <- c('a1','a2','a3','b1','b2','bu3','bu4','c1','c3')
code <- c('a','b','bu',c)
The structure of the data is somewhat like this -
countrya1 <- c("a","a","a")
yeara1 <- c("1","1","1")
inca1 <- c("1","2","3")
a1 <- data.frame(countrya1,yeara1,inca1)
countrya2 <- c("a","a","a")
yeara2 <- c("2","2","2")
inca2 <- c("1","4","3")
a2 <- data.frame(countrya2,yeara2,inca2)
countryb1 <- c("b","b","b")
yearb1 <- c("1","1","1")
incb1 <- c("1","2","7")
b1 <- data.frame(countryb1,yearb1,incb1)
countryb2 <- c("b","b","b")
yearb2 <- c("2","2","2")
incb2 <- c("6","2","3")
b2 <- data.frame(countryb2,yearb2,incb2)
The code that I used to combine all the datasets is as follows -
df=NULL
for (i in length(data)){
df1 <-read.dta(data[i])
df <-rbind(df,df1)
}
This binds all the datasets together in df.
Is there a way to bind a1,a2,a3 together and b1,b2,b3 together and so on. In short, I want to bind the datasets by 'code'. Is there a way to do it in R?
Thanks in advance for the help.

Answer 1

We can split the 'data' by creating a group without the numbers and then with read.dta, read the datasets and rbind the datasets of same name
lst <- lapply(split(data, sub("\\d+", "", data)),
function(x) do.call(rbind, lapply(x, read.dta)))
If we want to use the 'code', then use grep by looping through the 'code'
lapply(code, function(x) do.call(rbind, lapply(grep(x, data, value = TRUE), read.dta)))
data
code <- c('a','b','bu','c')