linked_list

class LinkedList():
    def __init__(self):
        self.start = None
        self.finish = None
        self.lenght = 0

    def __len__(self):
        return self.lenght

    def __str__(self):
        if self.lenght == 0:
            return 'Empty LinkedList'
        arr = ''
        temp = self.start
        for _ in range(self.lenght):
            arr += temp.data + '\n'
            if temp.next is None:
                return arr
            temp = temp.next

    def add_object_to_end(self, new_object):
        if self.start == None:
            self.start = new_object
            self.finish = new_object
        else:
            new_object.prev = self.finish
            self.finish.next = new_object
            self.finish = new_object
        self.lenght += 1

    def add_object_to_begin(self, new_object):
        if self.start == None:
            self.start = new_object
            self.finish = new_object
        else:
            new_object.next = self.start
            self.start.prev = new_object
            self.start = new_object
        self.lenght += 1

    def delete_object(self, object_data):
        obj = self.is_object(object_data)
        if self.lenght == 0:
            print('LinkedList is already empty')
        elif obj == self.finish:
            self.finish = obj.prev
            self.finish.next = None
            self.lenght -= 1
            print('Object was deleted')
        elif obj == self.start:
            self.start = obj.next
            self.start.prev = None
            self.lenght -= 1
            print('Object was deleted')
        elif obj:
            obj.prev.next = obj.next
            obj.next.prev = obj.prev
            self.lenght -= 1
            print('Object was deleted')
        elif not self.is_object(object_data):
            print('LinkedList has no that object')

    def is_object(self, object_data):
        if self.lenght == 0:
            return False
        temp = self.start
        for _ in range(self.lenght):
            if temp.data == object_data:
                return temp
            if temp.next is not None:
                temp = temp.next
            elif temp.next is None and temp.data == object_data:
                return temp
        return False

class LinkedListObject:
    def __init__(self, data):
        self.prev = None
        self.next = None
        self.data = data


obj1 = LinkedListObject('data1')
obj2 = LinkedListObject('data2')
obj5 = LinkedListObject('data5')
obj6 = LinkedListObject('data6')
obj7 = LinkedListObject('data7')
l_list = LinkedList()
l_list.add_object_to_end(obj1)
l_list.add_object_to_end(obj2)
l_list.add_object_to_end(obj5)
l_list.add_object_to_begin(obj6)
print(len(l_list))
print(l_list)
l_list.delete_object('data2')
print(len(l_list))
print(l_list)
l_list.add_object_to_end(obj7)
print(len(l_list))
print(l_list)