Create group_odd_and_even.py

linked_lists/group_odd_and_even.py

@@ -0,0 +1,31 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+# author: bt3gl
+
+class Node:
+
+   def __init__(self, val):
+       self.val = val
+       self.next = None
+
+
+def group_odd_and_even(head):
+        
+        if not head:
+            return None
+        
+        odd = head
+        even = odd.next
+        even_head = even
+        
+        while even is not None and even.next is not None:
+            
+            odd.next = even.next
+            odd = odd.next
+            even.next = odd.next
+            even = even.next
+        
+        odd.next = even_head
+        
+        return head
+