how to copy linked list in Python : class _ListNode:

    def __init__(self, value, next_):
        """
        -------------------------------------------------------
        Initializes a list node.
        Use: node = _ListNode(value, _next)
        -------------------------------------------------------
        Preconditions:
            _value - data value for node (?)
            _next - another list node (_ListNode)
        Postconditions:
            Initializes a list node that contains a copy of value
            and a link to the next node in the list.
        -------------------------------------------------------
        """
        self._value = copy.deepcopy(value)
        self._next = next_
        return
class List:

    def __init__(self):
        """
        -------------------------------------------------------
        Initializes an empty list.
        Use: l = List()
        -------------------------------------------------------
        Postconditions:
            Initializes an empty list.
        -------------------------------------------------------
        """
        self._front = None
        self._count = 0
        return
    def copy(self):
        """
        -------------------------------------------------------
        Duplicates the current list to a new list in the same order.
        Use: new_list = l.copy()
        -------------------------------------------------------
        Postconditions:
            returns:
            new_list - a copy of self (List)
        -------------------------------------------------------

        """
The requirement is to write the copy function.

But when I finish this function as my opinion the new list only contains one item or None item.

Does anyone could tell me how to finish this function?

Really appreciate for your help.