객체지향 프로그래밍으로 링크드 리스트 구현

# 객체지향 프로그래밍으로 링크드 리스트 구현
 
# set up
class Node:
    def __init__(self, data, next=None):
        self.data = data
        self.next = next
 
class NodeList:
    def __init__(self, data):
        self.head = Node(data)        
        
    def add(self, data):
        if self.head == '':
            self.head = Node(data)
        else:
            node = self.head
            while node.next:
                node = node.next      
            node.next = Node(data) 
 
    def showAll(self):
        node = self.head
        while node:
            print(node.data)
            node = node.next
    
    def delete(self, data):
        if self.head == '':
            print("현재 노드가 없습니다")
            return
        if self.head.data == data:
            temp = self.head
            self.head = temp.next
            del temp
        else:
            node = self.head                   
            while node.next:
                if node.next.data == data:
                    temp = node.next
                    node.next = node.next.next
                    del temp
                    return
                else:
                    node = node.next
    
    def search_node(self, data):
        node = self.head
        while node:
            if node.data == data:
                return node
            else:
                node = node.next
                
    
# 실행
linkedlist = NodeList(0)
 
print(linkedlist.head) # <__main__.Node object at 0x..>
 
linkedlist.delete(0) # head 제거 
linkedlist.head # 비어있음
 
linkedlist = NodeList(1)
 
for i in range(2, 4):
    linkedlist.add(i)
 
linkedlist.showAll() # 1, 2, 3
 
linkedlist.delete(2) # 2 삭제
linkedlist.showAll() # 1, 3
 
node_found = linkedlist.search_node(3)
print(node_found.data) # 3