设计整数单链表的基础运算程序

设计一个整数单链表基础运算是指创建链表结构，并实现常见的操作，如插入节点、删除节点、查找节点以及打印链表等。这里是一个简单的示例：

1. **定义链表节点**:

class ListNode:
    def __init__(self, val=0, next=None):
        self.val = val
        self.next = next

2. **初始化空链表**:

def create_empty_list():
    return ListNode()

3. **插入节点**:

def insert_node(head, val):
    new_node = ListNode(val)
    if not head:
        head = new_node
    else:
        current = head
        while current.next:
            current = current.next
        current.next = new_node
    return head

4. **删除节点** (假设给定值存在于链表中):

def delete_node(head, val):
    if not head:
        return None
    if head.val == val:
        return head.next
    current = head
    while current.next and current.next.val != val:
        current = current.next
    if current.next:
        current.next = current.next.next
    return head

5. **查找节点**:

def find_node(head, val):
    current = head
    while current:
        if current.val == val:
            return True
        current = current.next
    return False

6. **打印链表**:

def print_list(head):
    current = head
    while current:
        print(current.val, end=" -> ")
        current = current.next
    print("None")