AttributeError：“函数”对象没有属性“ get_value”

Question

只有在成功删除值之后，我才会收到AttributeError-请建议在打印值时是否有任何错误。该功能可以在删除之前正确打印

 class Node:
        def __init__(self, value=None, l_next=None):
            self.value = value
            self.l_next = l_next

        def get_value(self):
            return self.value

        def set_value(self, val):
            self.value = val

        def get_next_node(self):
            return self.l_next

        def set_next_node(self, n_next):
            self.l_next = n_next


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

        def add_node(self, value):
            new_node = Node(value, self.head)
            self.head = new_node

        def find_node(self, value):
            curr = self.head
            while curr:
                if curr.get_value() == value:
                    return True
                curr = curr.get_next_node()
            return False

        def del_node(self, val):
            curr = self.head
            prev = None
            while curr:
                if curr.get_value() == val:
                    if prev:
                        prev.set_next_node(curr.get_next_node)
                    else:
                        self.head = curr.get_next_node
                    print("Item Deleted")
                    return True
                prev = curr
                curr = curr.get_next_node()
            print("Item not available for Delete")
            return False

        def print_list(self):
            item_list = []
            curr = self.head
            while curr:
                item_list.append(curr.get_value())
                curr = curr.get_next_node()
            return item_list


    List1 = LinkedList()
    List1.add_node(4)
    List1.add_node(5)
    List1.add_node(1)
    List1.add_node(19)
    List1.add_node(41)
    List1.add_node(25)
    List1.add_node(40)
    List1.add_node(51)
    print(List1.print_list())
    print(List1.find_node(20))
    print(List1.find_node(5))
    List1.del_node(20)
    List1.del_node(5)
    print(List1.print_list())

输出：

[51, 40, 25, 41, 19, 1, 5, 4]
False
True
Item not available for Delete
Item Deleted

错误：

print(List1.print_list())
File "C:/Users/sv4/PycharmProjects/Sample/LinkedList.py", line 55, in 
print_list
item_list.append(curr.get_value())
AttributeError: 'function' object has no attribute 'get_value'      
Process finished with exit code 1