Django 使用QuerySet filter save, 發生‘QuerySet‘ object has no attribute ‘save‘错误解决办法?

我在操作py+Django 写网页，遇到QuerySet filter的save错误。
錯誤说’QuerySet’ object has no attribute ‘save’，也就是说這是一个集合QuerySet，而对于集合的话，是没有“save”这个属性。

请问该如何修正才能正确地修改? 谢谢

以下是提供我的程式代码

Models：

Software Table

class Software(models.Model):
    STATUS_CHOICES = [
        (0, '规划中'),
        (1, '开发中'),
        (2, '使用中'),
        (3, '已废弃')
    ]
    name = models.CharField(max_length=100, verbose_name="系统名称")
    url = models.CharField(max_length=100, verbose_name="系统网址")
    status = models.PositiveIntegerField(default=0, choices=STATUS_CHOICES,  verbose_name="目前状态") 
    company = models.ForeignKey(Company, on_delete=models.CASCADE,  verbose_name="开发公司或单位")
    team = models.ForeignKey(Team, on_delete=models.DO_NOTHING,  verbose_name="所属组别")
    def __str__(self):
        return self.name

Memo Table

class Memo(models.Model):
    notes = models.TextField()
    software = models.ForeignKey(Software, on_delete=models.CASCADE)
    #software = models.ForeignKey(Software, on_delete=models.SET_NULL, null=True, blank=True)
    timestamp = models.DateTimeField(default=timezone.now)
 
    def __str__(self):
        return self.notes

Templates：

{% extends 'base.html' %}
{% block title %}
查核系统
{% endblock %}
{% block main %}
<h2 >编辑备注</h2>
<hr>
<form action="/editmemo/" method="POST">
{% csrf_token %}
<input name="pk" type="hidden" value={{ target_memo.id }}>
<table class="table table-striped">
    <tr>
        <td align=right>备注：
        </td>
        <td>
            {% for memo in memos %}
            <input type=text name="memos" size=50  value='{{memo.notes}}'>
            {% endfor %}
        </td>
    </tr> 
    <tr><td>　</td><td>
        <input type=submit value="确定修改" class="btn btn-warning">
    </td></tr>
</table>
</form>
{% endblock %}

View：

@login_required(login_url='/admin/login/')
def edit_memo(request,pk=None):
    logged_user = User.objects.get(username=request.user.username)
    logged_user = UserProfile.objects.get(user=logged_user)
    teamid = Team.objects.get(name = logged_user.team).id
    target_soft = Software.objects.get( id = pk)
    item = Software.objects.get(id=pk)
    if request.method=="POST":
        softwareid = request.POST.get('softwareid')
        item = Software.objects.get(id=pk)
        memos = Memo.objects.filter(software=item)
        #Memo.objects.all().update(notes=memos)
        print(memos[0])
        memos[0].save()
        return render(request,"showdetail.html",locals())      
    try:
        memos = Memo.objects.filter(software=item)
    except:       
        return redirect("/showall/")
    return render(request, "edit_memo.html", locals())

Url：

urlpatterns = [
    path('editmemo/',views.edit_memo),
    path('editmemo/<int:pk>/',views.edit_memo),
    path('', views.index),
]+static(settings.MEDIA_URL,document_root=settings.MEDIA_ROOT)