在Python语言中删除LinkedList实现函数的一个问题

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

def deleteNode(head, val):
    # 判断要删除的节点是否是头节点
    if head.val == val:
        return head.next
    
    # 找到要删除节点的前一个节点
    prev = head
    curr = head.next
    while curr and curr.val != val:
        prev = curr
        curr = curr.next
    
    # 删除节点
    if curr:
        prev.next = curr.next
        curr.next = None
    
    return head