List reverse

gistfile1.py

#!/usr/bin/env python
class List(object):
    def __init__(self):
        self.val  = None
        self.next = None
    
    def add(self, val):
        current = self
        
        while current.next is not None:
            current = current.next
        
        current.val  = val
        current.next = List()
    
    def reverse(self):
        current  = self
        previous = None
        
        while current.next is not None:
            following = current.next
            current.next = previous
            previous = current
            current = following
        
        return previous