Django无法导入HttpResponseRedirect，即使我没有导入。

Question

以下是我的观点：

from django.shortcuts import render, redirect
from tshirts.forms import TShirtUploadForm, LoginForm
from tshirts.models import TShirt
from django.contrib.auth.decorators import login_required
from django.contrib.auth import authenticate, login, logout

def login(request):
    if request.method == "POST":
        username = request.POST['username']
        password = request.POST['password']
        user = authenticate(username, password)

        if user is not None:
            if user.is_active():
                login(request, password)
                return redirect('tshirts.views.upload')
    else:
        form = LoginForm()

    return render(request, "tshirts/login.html", {"form":form})


@login_required
def upload(request):
    if request.method == "POST":
        form = TShirtUploadForm(request.POST, request.FILES)
        if form.is_valid():
            tshirt = TShirt()
            tshirt.title = form.cleaned_data['title']
            tshirt.search_tag_1 = form.cleaned_data['search_tag_1']
            tshirt.search_tag_2 = form.cleaned_data['search_tag_2']
            tshirt.search_tag_3 = form.cleaned_data['search_tag_2']
            tshirt.design = form.cleaned_data['design']
            tshirt.save()

            return render(request, "tshirts/upload.html", {"form" : TShirtUploadForm(),
                                                           "success" : True,})
    else:
        form = TShirtUploadForm()

    return render(request, "tshirts/upload.html", {"form" : form})

尝试运行服务器时，出现以下错误：

^{pr2}$

我尝试过调试，但在这行出现了一个错误：

http/init.py:

from django.http.response import (HttpResponse, StreamingHttpResponse,
    CompatibleStreamingHttpResponse, HttpResponsePermanentRedirect,
    HttpResponseRedirect, HttpResponseNotModified, HttpResponseBadRequest,
    HttpResponseForbidden, HttpResponseNotFound, HttpResponseNotAllowed,
    HttpResponseGone, HttpResponseServerError, Http404, BadHeaderError)

我不明白是什么原因导致这台direct无法导入。我是不是做错了什么？在