reverse a linked list

class Solution:
    def reverseList(self, head: Optional[ListNode]) -> Optional[ListNode]:
        if head==None or head.next==None:
            return head
        def change(first,second):
            if second.next==None:
                second.next=first
                return second
            else:
                t=change(second,second.next)
                second.next=first
                return t
        head=change(None,head)
        return head