Python: how to remove the None in Linked List?

Question

I need to create a linked list in python as assessment for my university. Everything works fine, except for one little thing: the output shows "None" at the end. Example output 1, 5, 8, 9, None

How can I remove this None at the end? I tried many things but nothing, I don't know if the problem is the print_list() function or something else.

I test all the other functions, such as "size" and they work fine.

Please see my code below.

class Node():
    def __init__(self,data):    
        self.data = data
        self.next = None
    def get_data(self):       
        return self.data
    def get_next(self):
        if self.next is not None:    
            return self.next
    def set_data(self,newdata):  
        self.data = newdata
    def set_next(self,newnext):   
        self.next = newnext
    def __str__(self):            
        return str(self.data)

class UnorderedList():
    def __init__(self):      
        self.head = None
    def add(self,item):     
        tmp = Node(item)
        tmp.set_next(self.head)
        self.head = tmp
    def isEmpty(self):       
        return self.head == None
    def size(self):          
        current = self.head
        count = 0
        while current != None:
            count = count + 1
            current = current.get_next()
        return count
    def print_list(self):
        if self.head is None:
            return  
        node = self.head 
        while node is not None:
            print(node.__str__(), end = ' ')
            node = node.get_next()
       
        
my_list = UnorderedList()

my_list.add(2)
my_list.add(1)
my_list.add(5)
my_list.add(0)
my_list.add(8)
my_list.add(9)
my_list.add(1)
my_list.add(8)

print(my_list.print_list())

So, out of this code, my expectation was:

8, 1, 9, 8, 0, 5, 1, 2

But what I get is:

8, 1, 9, 8, 0, 5, 1, 2, None

I would appreciate any help, thank you so much.