使用Lapply保存文件时如何添加字符

Question

I have the following list

  L = list.files(".", ".txt")

which is

   a.txt
   b.txt
   c.txt

and I want to apply some code to all files in that list, but I want to save the dataframes with the samename plus some character to indicate that it is modified. For example

   a_modified.txt
   b_modified.txt
   c_modified.txt

I'm currently used this code:

   datalist = lapply(L, function(x) {
   DF = read.csv(x, sep = ",")
   DF$X = gsub("[:.:][[:digit:]]{1,3}","", DF$X))
   colnames(DF)[colnames(DF)=="X"] <- "ID"
   DF <- merge(DF, genes ,by="ID")
   write.csv(DF, x)
   return(DF)
   })

I tried using

   write.csv(DF, x+"_modified")

which was obviously wrong, as write.csv does not accept this exact operation.

Any ideas?

Answer 1

We need paste instead of +

write.csv(DF, paste0(sub("\\.txt", "", x), "_modified.csv"))

or this can be done within sub itself

write.csv(DF, sub("\\.txt", "_modified.csv", x))

NOTE: intial datasets were .txt