added code for swapping node positoin in linkedlist

Author: manthansubhash01

Python/Swap Nodes at Position K from Beginning and End.py

@@ -0,0 +1,19 @@
+'''
+class Node:
+    def __init__(self):
+        self.data = None
+        self.next = None
+        self.prev = None
+'''
+def swapNodes(head, k):
+    temp = head 
+    while temp.next is not None:
+        temp = temp.next
+    tail = temp
+    start = head
+    end = tail
+    while k > 1:
+        start = start.next
+        end = end.prev
+        k -= 1
+    start.data, end.data = end.data, start.data