python单链表使用

要使用Python实现单链表，可以定义一个Node类表示链表中的每个节点，以及一个LinkedList类表示整个表。下面是一个简单的单链表的Python实现：

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

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

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

    def prepend(self, data):
        new_node = Node(data)
        new_node.next = self.head
        self.head = new_node

    def insert_after_node(self, prev_node, data):
        if not prev_node:
            print("Previous node is not in the list")
            return
        new_node = Node(data)
        new_node.next = prev_node.next
        prev_node.next = new_node

    def delete_node(self, key):
        curr_node = self.head
        if curr_node and curr_node.data == key:
            self.head = curr_node.next
            curr_node = None
            return
        prev_node = None
        while curr_node and curr_node.data != key:
            prev_node = curr_node
            curr_node = curr_node.next
        if curr_node is None:
            return
        prev_node.next = curr_node.next
        curr_node = None

    def print_list(self):
        curr_node = self.head
        while curr_node:
            print(curr_node.data)
            curr_node = curr_node.next

这个实现包括了一些常用的操作，例如添加节点、在节点前插入节点、在节点后插入节点、删除节点和打印整个链表。可以使用以下代码测试这个实现：

llist = LinkedList()
llist.append("A")
llist.append("B")
llist.append("C")
llist.append("D")
llist.prepend("E")
llist.insert_after_node(llist.head.next, "F")
llist.delete_node("B")
llist.print_list()

输出应该是：

E
A
F
C
D