Merge rows in one data.frame

Question

This is a very similar question to merge-two-rows-in-one-dataframe but I have string variables and just want to collapse some rows that have the same country name. I adapted the

Answer 1

We could use data.table. We convert the 'data.frame' to 'data.table' (setDT(data)), grouped by 'name', we unlist the columns specified in the .SDcols, and paste it together.

library(data.table)
setDT(data)[, unlist(.SD), name, .SDcols=v1:v4][V1!='', paste(V1, collapse=', '), name]

As the expected output is not showed, it could be also

setDT(data)[, lapply(.SD, function(x) paste(x[x!=''], collapse='')) , name, .SDcols= v1:v4]

Update

Based on the expected output, we convert the 'factor' columns ('v1:v4') to 'character' class, then use the formula method of aggregate and paste the columns grouped by 'name'.

data[3:6] <- lapply(data[3:6], as.character)
aggregate(.~name, data[-1], FUN=function(x) paste(x[x!=''], collapse=', '))