NW| 26-Jul-SDC | Ahmad Hmedan | Sprint 2 | Implement a linked list in Python

Sprint-2/implement_linked_list/linked_list.py

@@ -0,0 +1,56 @@
+class LinkedList:
+    class Node:
+        __slots__ = ("next","previous","value")
+
+        def __init__(self, value):
+            self.next = None
+            self.previous = None
+            self.value = value
+
+    def __init__(self):
+        self.head = None
+        self.tail = None
+        self.size = 0
+
+    def push_head(self, value):
+        new_node = self.Node(value=value)
+        if self.head == None:
+            self.head = new_node
+            self.tail = new_node
+        else:
+            new_node.next = self.head
+            self.head.previous = new_node
+            self.head = new_node
+        self.size += 1
+        return new_node
+
+    def pop_tail(self):
+        if self.tail == None:
+            return
+        removed_value = self.tail.value
+
+        self.remove(self.tail)
+        return removed_value
+
+
+    def remove(self, node):
+        if node == None:
+            return
+        if node == self.head and node == self.tail:
+            self.head = None
+            self.tail = None
+
+        elif node == self.head:
+            self.head = self.head.next
+            self.head.previous = None
+
+        elif node == self.tail:
+            self.tail = self.tail.previous
+            self.tail.next = None
+
+        else:
+            node.next.previous = node.previous
+            node.previous.next = node.next
+        node.next = None
+        node.previous = None
+        self.size -= 1