Im a newbie to code so im quite bad at it. Im using Django for the framework. Currently this is my html code for the user input.

```
<html>
<head>
  <title>uploader</title>
  <style>
    h1 {
      font-size: 2em;
      font-weight: bold;
      color: #777777;
      text-align: center
    }
    table {
      margin: auto;
    }
    a {
      text-decoration: none
}
  </style>
</head>

<body>

   <h1>
      {{what}}
      <h3><p style="text-align: left;text-decoration: none;"><a href="{% url 'home' %}">Back</p></a></h3>
  </h1>
 <hr>
  <table>
    <tr>
      <td>
        <form action="upload/" method="POST" enctype="multipart/form-data">
 {% csrf_token %}
 <fieldset>
   Category of the device:<br>
   <input type="text" name="category" value="" required id="cat">
   <br>
   Model:<br>
   <input type="text" name="model" value="" required id="mod">
 <br>
          <input type="submit" value="Upload File" class="submit" name="submit" />
 <input type="file" name="file"/>

 </fieldset>

        </form>

      </td>
    </tr>
  </table>

</body>

</html>

```

views.py

```
def home(request):
    return render(request, 'index.html', {'what':'Upload Files'})

def upload(request):
try:
    if request.method == 'POST' and request.FILES['file']:
        try:    
            myfile = request.FILES['file']
            category = request.POST['category']
            model = request.POST['model']
            validate_file_extension(myfile)
            fs = FileSystemStorage(location='uploaded/')
            filename = request.FILES['filename'].name
            handle_uploaded_file(request.FILES['file'], str(request.FILES['file']))
            modified_name = "{}_{}_{}".format(filename, category, modle)
            filename = fs.save(modified_name, myfile)
            return redirect("/success")
        except:
            return redirect("/unsuccessful")
except:
    return redirect("/upload")

def handle_uploaded_file(file, filename):
    if not os.path.exists('uploaded/'):
        os.mkdir('uploaded/')
    with open('uploaded/' + filename, 'wb+') as destination:
        for chunk in file.chunks():
            destination.write(chunk)

```

How do i rename the file that the user uploaded to have the text they input to the back of their filename with "\_". 

eg: 

```
filename = myfile
category = camera 
model    = XYZ123

```

The file should be renamed to "myfile\_camera\_XYZ123".