leetcode之Remove Duplicates from Sorted List

# Definition for singly-linked list.
# class ListNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.next = None

class Solution(object):
def deleteDuplicates(self, head):
"""
:type head: ListNode
:rtype: ListNode
"""
if head == None:
return None
list1 = head
p = list1.val
while list1.next != None:
if list1.next.val == p:
list1.next = list1.next.next
continue
else:
p = list1.next.val
list1 = list1.next
return head