def print_items(x):
    """prec: x is a list or a tuple
postcondtion:  Each item of the list is printed on its own line."""
    #whodunit: jonathan
    if len(x) == 0:    ## is there more elephant
        return
    first = x[0]
    rest = x[1:]
    print_items(rest) # eat the rest
    print(first)      #take a spoonful
print_items(("a", "b", "c", "dingo", "elephant", "ferret"))