不全，请帮我弥补完整

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
        else:
            curr_node = self.head
            while curr_node.next:
                curr_node = curr_node.next
            curr_node.next = new_node

    def delete(self, data):
        if self.head and self.head.data == data:
            self.head = self.head.next
            return

        curr_node = self.head
        prev_node = None

        while curr_node:
            if curr_node.data == data:
                prev_node.next = curr_node.next
                return
            prev_node = curr_node
            curr_node = curr_node.next

    def search(self, data):
        curr_node = self.head
        while curr_node:
            if curr_node.data == data:
                return True
            curr_node = curr_node.next
        return False