单链表逆置

代码如下：

class Node(object):
    def __init__(self,data,next=None):
        self.data = data
        self.next = next

def fun(node):
    p = node
    m = p
    cur = node.next
    while cur:
        tmp = cur.next
        cur.next = p
        p = cur
        cur = tmp
    m.next = None
    return p

if __name__ == "__main__":
    l1 = Node(1)
    l1.next = Node(2)
    l1.next.next = Node(3)
    l1.next.next.next = Node(4)
    l1 = fun(l1)
    while True:
        print(l1.data)
        l1 = l1.next
        if l1 == None:
            break