message: Update middle-of-the-linked-list.py
diff: @@ -34,7 +34,7 @@ class Solution(object):
  :type head: ListNode
  :rtype: ListNode
  """
  - slow, quick = head, head
  - while quick and quick.next:
  - slow, quick = slow.next, quick.next.next
  + slow, fast = head, head
  + while fast and fast.next:
  + slow, fast = slow.next, fast.next.next
  return slow
  