I am using `pdftk` for processing a PDF file.

```
new_doc.save()
url = "/docs/" +settings.MEDIA_URL + new_doc.pdf_file.name
command = 'pdftk '+url+" dump_data_fields" 

```

The problem is that I have to use `new_doc.save` before `pdftk`.

Is there any way to get `pdftk` to process the file without saving it?