The Viral Code

class Node(object):
    
    def __init__(self,value):
        
        self.value = value
        self.nextnode = None
def reverse(head):
    
    # Set up current,previous, and next nodes
    current = head
    previous = None
    nextnode = None

    # until we have gone through to the end of the list
    while current:
        nextnode = current.nextnode

        # Reverse the pointer ot the next_node
        current.nextnode = previous

        # Go one forward in the list
        previous = current
        current = nextnode

    return previous

# Create a list of 4 nodes
a = Node(1)
b = Node(2)
c = Node(3)
d = Node(4)
e = Node(5)

# Set up order a,b,c,d with values 1,2,3,4
a.nextnode = b
b.nextnode = c
c.nextnode = d
d.nextnode = e

print a.nextnode.value
print b.nextnode.value
print c.nextnode.value
print d.nextnode.value
print e.nextnode

reverse(a)

print 'after reverse----'
print e.nextnode.value
print d.nextnode.value
print c.nextnode.value
print b.nextnode.value
print a.nextnode