What is wrong with this code? (Attempting to add items from one list to another without duplicates) :     duplist = [5,9,14,3,9,97,4,3,23,85,123,5]

    singlist = []

    for i in (duplist) :
        if i != singlist :
            [str(i)] + singlist
            print(singlist)



I am attempting to add all of the items from duplist into singlist without adding the duplicates.  The result I get from this code is an empty list.  I believe the error is in my if statement line, although I am not sure what operator to use instead of !=

Thank you