什麼都不說上程式碼，歡迎指正

#coding:utf8


class Node():
    def __init__(self,val,nt = None):
        self.value = val
        self.next = nt
        
#迴圈連結串列實現        
class xunList():
    def __init__(self):
        self.headNode = Node(None,None)
        self.headNode.next = self.headNode
        self.head  = self.headNode
        self.size = 0
    def  __str__(self):
        if self.size ==  0:
            return 'empty'
        s = ''
        fin = self.head.next.next
        while fin.value:
            s += str(fin.value)
            if fin.next.value:
                s += ','
            fin = fin.next
            
           
        return s
        
    def addElement(self,value):
        elementNode = Node(value,None)
        if self.head.value ==  None:
            elementNode.next = self.headNode
            self.head.next = elementNode
            self.head = elementNode
            self.size += 1
        else:
            elementNode.next = self.headNode
            self.head.next = elementNode
            self.head = elementNode
            self.size += 1

    def search(self,index):
        if self.size == 0:
            return 'empty'
        if index > self.size:
            return 'out of index'
        i = 0
        se = self.head.next
        while i <= self.size:
            if i == index:
                break
            se = se.next
            i += 1
        return se.next.value
        
        
    def delete(self,data):
        if self.size == 0:
            return 'empty'
        de = self.head
        cur = self.head.next
        while cur != self.head:
            if cur.value ==  data:
                break
            de = cur
            cur = cur.next 
        if cur  == self.head:
            return 
        de.next = cur.next
        self.size -= 1
        
        
    


if __name__=="__main__":
    x = xunList()
    x.addElement('s')
    x.addElement(1)
    x.addElement('sd')
    x.addElement('yyu')