How to use the robotframework.models.Webcasestep.objects.all function in robotframework

def maoyan_test(request):
    username = request.session.get('user', '')
    tasks = Webcasestep.objects.all()
    if request.method == "POST":
        upperlevel_id = request.POST.get("casename_id")
        write_to_txt(upperlevel_id)
        time.sleep(1)
        readwebcaseSQL(upperlevel_id)
    return render(request, "webcasestep_manage.html",{"user": username, "tasks": tasks})

def remove_test_txt(request):
    username = request.session.get('user', '')
    tasks = Webcasestep.objects.all()
    if request.method =="POST":
        txtname = request.POST.get("casename_id")
        remove_webtest_txt(txtname)
    return render(request, "webcasestep_manage.html", {"user": username, "tasks": tasks})

def delete_web_casesteps(request):
    webcaseid = request.POST.get("casename_id")
    username = request.session.get('user', '')
    webcase = Webcase.objects.get(id=webcaseid)
    webcasesteps = Webcasestep.objects.all()
    stepid = request.POST.get("step_id")
    Webcasestep.objects.filter(Webcase_id=webcaseid,id=stepid).delete()
    return render(request, "webcasestep_manage.html",{"user": username, "webcasesteps": webcasesteps, "webcase": webcase})

def display_web_casesteps(request):
    username = request.session.get('user', '')
    webcaseid = request.GET.get('webcase.id',None)
    webcase = Webcase.objects.get(id=webcaseid)
    keywords = Webcase_keywords.objects.all()
    webcasesteps = Webcasestep.objects.all()
    return render(request,"webcasestep_manage.html",{"user": username,"webcasesteps":webcasesteps,"webcase":webcase,"keywords":keywords})