I have a list of lists, a list of file paths for some number of directories.

I want to import that files as lists of lists, where instead of getting one massive 1D list, the distinct directories are preserved from which the imported data goes into.

filePaths={{"/dir1/a.txt", "/dir1/b.txt", "/dir1/c.txt"},  {"/dir2/d.txt", 
  "/dir2/e.txt", "/dir2/f.txt"}}

Import[#,"Table"]& @/filePaths[[a]]&/@Range[Length[filePaths]]

I tried using a double mapping method, but mathematica gets upset when I try to do it, even though trying Print[] as follows gives me the expected file paths

Print[#] & /@ filePaths[[a]] & /@ Range[Length[filePaths]]
  • $\begingroup$ How are you using a if is not defined? To clarify your question, you basically want n lists with m files within, where n is your number of directories? (what do you mean by 'directories are preserved'? $\endgroup$ Oct 6, 2019 at 1:23
  • $\begingroup$ yes, I'm trying to get n lists of m files (by preservation I mean that all the files associated with a given dir are in the list). this would define a but doesn't resolve it Print[#] & /@ filePaths[[a]] & /@ Table[a, {a, 1, Length[filePaths]}] $\endgroup$ Oct 6, 2019 at 1:33

1 Answer 1


You can import the data into a list with n elements, each element having in itself m tables imported.

For instance, assuming every dataset you care about is in a separate .txt file within each of the directories, you can do:

directories={"C:\\dir1", "C:\\dir2"} (list your directories of interest)

myData = Table[Import[#, "Table"] & /@ 
  FileNames["*.txt", directories[[a]]], {a, 1, Length[directories]}];

This makes a list of length n, containing the data of every .txt file found in every one of the directories in directories.

I hope this helps.

  • $\begingroup$ Note that I list the directories, not the full path files (the full path file is detected with FileNames, which searches for files ending in "*.txt" -the asterisk is to mean that the file name can be anything, only the termination .txt matters-) $\endgroup$ Oct 6, 2019 at 1:42
  • $\begingroup$ I was able to modify the wildcard :-) thank you!!! $\endgroup$ Oct 6, 2019 at 1:48

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