How can I create a loop to create a new variable for different dataframes

Question

I would like to know how to create a loop to create the same new variable for 7 different dataframes. Currently, my code looks like this:

m1_02 <- m1_02 %>% mutate(hhid = xa*10^5 + hoso)
m2_02 <- m2_02 %>% mutate(hhid = xa*10^5 + hoso)
m3_02 <- m3_02 %>% mutate(hhid = xa*10^5 + hoso)
m3_02a <- m3_02a %>% mutate(hhid = xa*10^5 + hoso)
m6a2_02 <- m6a2_02 %>% mutate(hhid = xa*10^5 + hoso)
m6b1_02 <- m6b1_02 %>% mutate(hhid = xa*10^5 + hoso)
m6b2_02 <- m6b2_02 %>% mutate(hhid = xa*10^5 + hoso)

I was wondering if there was a way I could create a loop that would create the hhid variable in the respective dataframes without having to use the mutate function one by one.

Thank you!

Since you're doing the same thing to multiple frames, it's likely better to work with a [list of frames](https://stackoverflow.com/a/24376207/3358227) instead of keeping them as separate objects. — r2evans, Jan 19 '22 at 17:04

score 2 · Answer 1 · answered Jan 19 '22 at 17:04

It may be better to load the datasets into a list and then perform the operation at once and store the output in a list instead of creating more objects in the global env

library(purrr)
library(dplyr)
lst1 <- mget(ls(pattern = "^m.*\\d+_\\d+$")) %>%
    map(~ .x %>%
            mutate(hhid = xa * 10^5 + hoso))

If we need to update the original object, use list2envon the output list

list2env(lst1, .GlobalEnv)

How can I create a loop to create a new variable for different dataframes

1 Answers1