使用python建立迴圈單鏈表程式碼如下：

# coding:utf-8


class Node(object):
    """節點"""
    def __init__(self, elem):
        self.elem = elem
        self.next = None


class SingleCycleLinkList(object):
    """單向迴圈連結串列"""
    def __init__(self, node=None):
        self.__head = node
        if node:
            node.next
 
=node

    def is_empty(self):
        """連結串列是否為空"""
        return self.__head == None

    def length(self):
        """連結串列長度"""
        # cur遊標，用來移動遍歷節點
        if self.is_empty():
            return 0
        cur = self.__head
        # count記錄數量
        count = 1#計數從1，因為依據下述的迴圈條件，cur走到尾節點時不進入迴圈，此時count值不包含尾節點
        
 
while cur.next != self.__head:
            count += 1
            cur = cur.next
        return count

    def travel(self):
        """遍歷整個連結串列"""

        if self.is_empty():
            return
        cur = self.__head
        #若連結串列為空，則cur.next不存在，迴圈會出問題，故先判斷是否為空連結串列
        while cur.next !=self.__head:
            print(cur.elem, end
 
=" ")
            cur = cur.next
        #當cur指向尾節點時即退出迴圈，故尾節點此時並未進行列印，下述語句列印尾節點
        print(cur.elem)


    def add(self, item):
        """連結串列頭部新增元素，頭插法"""
        node = Node(item)
        #先判斷連結串列是否為空，若為空執行if內語句
        if self.is_empty():
            self.__head=node
            node.next=node
        else:
        #連結串列不為空，建立一個遊標找到其尾部節點
            cur=self.__head

            while cur.next!=self.__head:
                cur=cur.next
            node.next = self.__head
            self.__head = node
            cur.next=node


    def append(self, item):
        """連結串列尾部新增元素, 尾插法"""
        node = Node(item)
        #先判斷連結串列是否為空，為空執行if語句
        if self.is_empty():
            self.__head = node
            node.next=self.__head
        else:
            #連結串列不為空
            cur = self.__head
            while cur.next != self.__head:
                cur = cur.next
            node.next=cur.next
            cur.next=node

    def insert(self, pos, item):
        """指定位置新增元素
        :param  pos 從0開始
        """
        node = Node(item)
        if pos <= 0:
            self.add(item)
        elif pos > (self.length()-1):
            self.append(item)
        else:
            #從中間部分插入與單鏈表一致，故無需進行改變
            pre = self.__head
            count = 0
            while count < (pos-1):
                count += 1
                pre = pre.next
            # 當迴圈退出後，pre指向pos-1位置

            node.next = pre.next
            pre.next = node

    def remove(self, item):
        """刪除節點"""
        cur = self.__head
        pre = None
        if self.is_empty():
            #判斷連結串列是否為空
            self.__head=None
            return
        while cur.next!=self.__head:
            #遍歷連結串列
            if cur.elem == item:
                # 先判斷cur是否等於item

                if cur == self.__head:
                    # 判斷相等的節點是否是頭節點
                        #刪除頭節點，先增加一個遊標mov指向尾節點
                        mov=self.__head
                        while mov.next!=self.__head:
                            mov=mov.next
                        self.__head=cur.next
                        mov.next=self.__head
                else:#中間節點
                    pre.next=cur.next
                return
            else:
                pre = cur
                cur = cur.next
        #跳出迴圈，cur指向尾節點
        if cur.elem==item:
            if cur == self.__head:
                # 判斷是否僅一個節點
                self.__head = None
            else:
                pre.next = cur.next


    def search(self, item):
        """查詢節點是否存在"""
        #先判斷是否空連結串列
        if self.is_empty():
            return False
        else:
            cur = self.__head
            while cur.next!=self.__head:
                if cur.elem == item:
                    return True
                else:
                    cur = cur.next
            #判斷尾節點是否等於查詢的引數
            if cur.elem==item:
                return True
            return False



if __name__ == "__main__":
    ll = SingleCycleLinkList()
    print(ll.is_empty())
    print(ll.length())
    ll.append(1)
    print(ll.is_empty())
    print(ll.length())
    ll.append(2)
    ll.travel()
    ll.add(8)
    ll.travel()
    ll.append(3)
    ll.add(4)
    ll.append(5)
    ll.insert(-1, 9)
    ll.travel()
    ll.insert(3, 100)
    ll.travel()
    ll.insert(10, 200)
    ll.travel()
    ll.remove(100)
    ll.travel()
    ll.remove(9)
    ll.travel()
    ll.remove(200)
    ll.travel()
    print(ll.search(8))

執行輸出：

參考學習視訊：https://www.bilibili.com/video/BV18W411T7Vv?p=16