Linked list

class Element():
    def __init__(self, value):
        self.value = value
        self.next = None


class LinkedList():
    def __init__(self, head=None):
        self.head = head

    def append(self, new_element):
        current = self.head
        if self.head:
            while current.next:
                current = current.next
            current.next = new_element
        else:
            self.head = new_element

    def get_position(self, position):
        """Get an element from a particular position.
        Assume the first position is "1".
        Return "None" if position is not in the list."""
        current = self.head
        counter = 1

        while current:
            if counter == position:
                return current
            elif counter > position:
                return None
            else:
                counter += 1
                current = current.next

    def insert(self, new_element, position):
        """Insert a new node at the given position.
        Assume the first position is "1".
        Inserting at position 3 means between
        the 2nd and 3rd elements."""

        current = self.head
        position_found = False
        counter = 1

        if position == 1:
            self.head = new_element
            self.head.next = current
            return
        while not position_found:
            if counter == position-1:
                position_found = True
                new_element.next = current.next
                current.next = new_element
                return
            else:
                current = current.next
                counter += 1

    def delete(self, value):
        """Delete the first node with a given value."""
        current = self.head
        previous = None

        if current.value == value:
            self.head = current.next
            return
        while current.next:
            if current.value == value:
                previous.next = current.next
            previous = current
            current = current.next
        return


# Test cases
# Set up some Elements
e1 = Element(1)
e2 = Element(2)
e3 = Element(3)
e4 = Element(4)

# Start setting up a LinkedList
ll = LinkedList(e1)
ll.append(e2)
ll.append(e3)

# Test get_position
# Should print 3
# print(ll.head.next.next.value)
# # Should also print 3
# print(ll.get_position(3).value)


# Test insert
ll.insert(e4, 3)
# Should print 4 now
# print(ll.get_position(3).value)
# Test delete
ll.delete(1)
# Should print 2 now
print (ll.get_position(1).value)
# Should print 4 now
print (ll.get_position(2).value)
# Should print 3 now
print (ll.get_position(3).value)