单链表 Python

好的，以下是 Python 实现单链表的代码：

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

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

    def addAtHead(self, val):
        new_node = Node(val)
        new_node.next = self.head
        self.head = new_node

    def addAtTail(self, val):
        new_node = Node(val)
        if not self.head:
            self.head = new_node
            return
        cur = self.head
        while cur.next:
            cur = cur.next
        cur.next = new_node

    def get(self, index):
        if index < 0 or not self.head:
            return -1
        cur = self.head
        for i in range(index):
            if not cur.next:
                return -1
            cur = cur.next
        return cur.val

    def addAtIndex(self, index, val):
        if index <= 0:
            self.addAtHead(val)
            return
        cur = self.head
        for i in range(index-1):
            if not cur:
                return
            cur = cur.next
        new_node = Node(val)
        new_node.next = cur.next
        cur.next = new_node

    def deleteAtIndex(self, index):
        if index < 0 or not self.head:
            return
        if index == 0:
            self.head = self.head.next
            return
        cur = self.head
        for i in range(index-1):
            if not cur.next:
                return
            cur = cur.next
        if not cur.next:
            return
        cur.next = cur.next.next