<snip> Thanks for all, I found the problems I faced is more tricky than the simple list I gave.
Here the list is: a row of numbers, not one number, such as print a_list[1] is: 1 1 9 7 7 9 9 9 print(a_list) is: 617 617 790 571 571 790 790 790 I attached the codes written based on the suggestions all you have given, and also attached the to-be-handled file in the following link: #!/usr/bin/python3 import os.path INFILEEXT=".out" OUTFILEEXT=".bri" atoms=[] def fetchonefiledata(infilename): for line in open(infilename,"r"): parts=line.strip().split() atoms=parts[2] print(atoms[0]) def remove_coming_duplications(a_list): for idx, element in enumerate(a_list): if element != a_list[idx-1]: print(element) if __name__=="__main__": for filename in os.listdir("."): base, ext = os.path.splitext(filename) if ext == INFILEEXT: fetchonefiledata(filename) remove_coming_duplications(atoms) https://docs.google.com/open?id=0B93SVRfpVVg3MjVlODdiOWYtY2FlYy00NDIzLThjMzAtMDk0NTQ4ZTRjZjRh Thanks with best regards, P.S My primary interest is getting the lists from different files, hopefully in the end find some rules between those numbers. or pathway, such as 1 2 4 8 7 6 4 8 7 6 5 1 so it shares a feature of 4 -> 8 -> 7 -> 6. _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor