importing multiple csv into 1 table

Sorry, was hijacked to do another project so I didn't have time to work on this side project of mine.

JBeaucaire, I think I must be doing something wrong here. I tried the code and it didn't work as intended. Can we start again ...

Input file: marketsummary_all.txt (a csv file)
Output file: aggregate_marketsummary.txt

When I tried to run your code on marketsummary_all.txt (after commenting out the joining/importing bits), it only read the first date and put it in every row of col A. Any ideas?