Remove Duplicates from Sorted List

My Solution:

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, val=0, next=None):
#         self.val = val
#         self.next = next

def deleteDuplicates(head: Optional[ListNode]) -> Optional[ListNode]:
        # empty or single item list
        if not head or not head.next:
                return head

        cur_node = head

        while cur_node.next:
                nxt_node = cur_node.next

                if cur_node.val == nxt_node.val:
                        cur_node.next = nxt_node.next
                else:
                        cur_node = cur_node.next
                        nxt_node = nxt_node.next

        return head