After which you would have the original data frames as elements of dflst, and the processed data frames as elements of newdf. The loop can be simplified a bit if you don't need to keep copies of the original data frames.
With this approach, it would be better create dflst using a loop over the incoming file names, running read.csv() inside the loop. In which case you would never create separate data frames df_bs_id1, df_bs_id2, etc.
I have used both approaches at various times over the years, and each has pros and cons. In general, I would recommend the list approach, however, especially if you have a large number of files to process.
Lawrence Livermore National Laboratory
7000 East Ave., L-627
Livermore, CA 94550
Lab cell 925-724-7509