having trouble with mathematica using nested lists. I want to save a list like this:


So, the nested components do not have an identical dimension. However, whenever I save the file (as csv or xls) and reimport it seems that the inner lists (like l1[[1,2]] is transformed into a string which I would like to bypass somehow.

  • 2
    $\begingroup$ If your aim is to re-import into Mathematica, use a format that can store arbitrary Mathematica expressions. This includes the "WDX", "Package" and "MX" Export formats. Some prefer using Compress and exporting the result as a "String". Note that "MX" is not cross-version-compatible and not cross platform before v10. $\endgroup$
    – Szabolcs
    Apr 15, 2015 at 0:05
  • $\begingroup$ Related: (2008) $\endgroup$
    – Mr.Wizard
    Apr 15, 2015 at 1:28
  • 1
    $\begingroup$ "CSV stores tabular data." More specifically, it stores ragged-right 2D arrays. XLS stores a set of sparse 2D arrays and some metadata. They are simply not capable of encoding nested lists of arbitrary depth. $\endgroup$ Apr 15, 2015 at 3:14
  • $\begingroup$ thanks a lot for the clarification with the *.csv and *.xls-files. The MX-package works fine, too! $\endgroup$
    – noclue11
    Apr 15, 2015 at 13:38

1 Answer 1



l1 = {{a1, {a, b, c, d, e}}, {a2, {f, g, h, i}}};

one exports using


and imports next with


If you don't SetDirectory, it will go to home directory and be then imported from there also.

See also this answer.

  • $\begingroup$ Does that really resolve the issue here? Essentially, I am not able to access the parts of my nested lists because some are simply converted to a string? $\endgroup$
    – noclue11
    Apr 14, 2015 at 16:22
  • $\begingroup$ I updated the answer providing a working example. $\endgroup$
    – corey979
    Apr 14, 2015 at 23:06

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