无头结点的单链表python代码

class Node:
def __init__(self, data):
self.data = data
self.next = None

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

def add_node(self, data):
new_node = Node(data)
if self.head is None:
self.head = new_node
return
current = self.head
while current.next is not None:
current = current.next
current.next = new_node

def delete_node(self, data):
if self.head is None:
return
if self.head.data == data:
self.head = self.head.next
return
current = self.head
while current.next is not None:
if current.next.data == data:
current.next = current.next.next
return
current = current.next

def print_list(self):
current = self.head
while current is not None:
print(current.data, end=' ')
current = current.next

# create a linked list
my_list = LinkedList()

# add nodes
my_list.add_node(1)
my_list.add_node(2)
my_list.add_node(3)
my_list.add_node(4)

# print the list
my_list.print_list()

# delete a node
my_list.delete_node(3)

# print the updated list
my_list.print_list()