如何在django中提示用户将pdf文件保存到本地机器？

# views.py
from django.shortcuts import render, redirect
from django.contrib import messages

def upload_pdf(request):
    if request.method == 'POST':
        file = request.FILES['file']
        with open('path/to/save/file.pdf', 'wb') as f:
            f.write(file.read())
        messages.success(request, '文件保存成功！')
        return redirect('upload_pdf')
    return render(request, 'upload_pdf.html')

<!-- upload_pdf.html -->
<form method="post" enctype="multipart/form-data">
  {% csrf_token %}
  <input type="file" name="file">
  <button type="submit">上传</button>
</form>

{% messages %}