Swap nodes in a linked list without swapping data

Author: IN\abhinav.singh

Linked List/swapNodes.py

@@ -1,43 +1,42 @@
-class Node:
-    def __init__(self,data):
-        self.data = data
+class Node(object):
+    def __init__(self, d):
+        self.data = d
         self.next = None
 
-class LinkedList:
+class LinkedList(object):
     def __init__(self):
         self.head = None
     def push(self, new_data):
-        new_node = Node(new_data)
-        new_node.next = self.head
-        self.head = new_node
-    def swapNodes(self,x,y):
+        new_Node = Node(new_data)
+        new_Node.next = self.head
+        self.head = new_Node
+    def swapNodes(self, x, y):
         if x == y:
             return
         prevX = None
         currX = self.head
-        while (currX != None and currX.data !=x):
+        while currX != None and currX.data != x:
             prevX = currX
             currX = currX.next
-        
         prevY = None
         currY = self.head
-        while (currY != None and currY.data!= y):
+        while currY != None and currY.data != y:
             prevY = currY
             currY = currY.next
-        
-        if (currX == None) or (currY == None):
+
+        if currX == None or currY == None:
             return
-        
+
         if prevX != None:
-            prevX.next = currX
-        else:
-            self.head = currX
-        
-        if prevY != None:
-            prevY.next = currY
-        else:
+            prevX.next = currY
+        else: 
             self.head = currY
 
+        if prevY != None:
+            prevY.next = currX
+        else: 
+            self.head = currX
+
         temp = currX.next
         currX.next = currY.next
         currY.next = temp
@@ -48,18 +47,16 @@ def printList(self):
             print(tNode.data,end=' ')
             tNode = tNode.next
 
-# Driver program to test above function
 llist = LinkedList()
- 
-# The constructed linked list is:
-# 1->2->3->4->5->6->7
+
 llist.push(7)
 llist.push(6)
 llist.push(5)
 llist.push(4)
 llist.push(3)
 llist.push(2)
 llist.push(1)
+
 print ("Linked list before calling swapNodes(4,3) ")
 llist.printList()
 llist.swapNodes(4, 3)