python - Removing a node from a linked list with "del" doesn't work -

the problematic part in function remove. after del called, relevant node not removed linked list. did misunderstand del?

class node:     def __init__(self, val):         self.val = val         self.next = none      def add(self, val):         if not (self.next):             self.next = node(val)         else:             self.next.add(val)      def remove(self, val):         if self.val == val:             if self.next:                 self.val = self.next.val                 self.next = self.next.next             else:                 del self # doesn't remove node linked list          else:             if self.next:                 self.next.remove(val)             else:                 print "no such val found %d" % val      def __str__(self):         output = []         while self not none:             output.append(str(self.val))             self = self.next         return " -> ".join(output)   head = node(1) head.add(2) print head head.remove(3) head.add(3) head.add(4) print head head.remove(3) head.remove(4) print head 

the statement del self removes name self local scope (and decrements reference count). has no effect on other references nor objects.

to remove node linked list, must update node(s) refer it. since have singly linked list, must traverse list beginning find node node.next == self, change node.next = self.next remove self sequence of links.