python数据结构---链式线性表

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

class LinkList(object):
    def __init__(self):
        self.head=ListNode(None)#头节点
    def Empty(self):#判空
        if self.head.next==None:
            return True
        else:
            return False

    def initwei(self,e):#尾插
        p=self.head
        while p.next:
            p=p.next
        q = ListNode(e)
        p.next=q


    def inittou(self,e):#头插
        q = ListNode(e)
        q.next=self.head
        self.head=q


    def Get(self,i):#查找第i个点
        if self.Empty():
            return None
        j=0
        p=self.head
        while p.next!=None and j