[Tutor] finding non unique data in lists

[Scott Melnyk]

Hello!

I have a collection of lists of different lengths (containing exons
from genetic data) that I would like to compare and only keep the
those that are found within each of the lists.  Any exon not present
in all the lists is not important to me.

I am new to python and was told that sets could be used easily to find
the unique data but I am unsure the most efficient way how to pull out
the non-unique data.

All suggestions are very much appreciated and welcome.


-- 
Scott