Read uploaded file into string using Django

Question

I'd like to read an uploaded file into a string. The file is not allowed if it is greater than 100k in size.

I've got the following code, but when I step through it using pdb, data is empty after the data = file.read() line executes.

def import_data(request):
    params = {}
    if request.method == 'POST':
        pdb.set_trace()
        form = UploadFileForm(request.POST, request.FILES)
        if form.is_valid():
            file = request.FILES['file']
            data = file.read()
            update_database(data)
    else:
        form = UploadFileForm()
    params['form'] = form
    return render_to_response('import_data.html',
                                params,
                                context_instance=RequestContext(request))

And this is my template:

% extends 'base.html' %}
{% block content %}

    <form enctype="multipart/form-data" action="" method="post">{% csrf_token %}
        {{ form.as_p }}
        <input type="submit" value="Submit" />
    </form>
{% endblock %}

Any ideas how to fix this?

Answer 1

Have you looked into "Chunking" your uploads. What this basically does, is break your upload into multiple "chunks" as it saves it to the disk. I think this will help you upload larger files.

Regarding the empty file after "data = file.read()" executes, I think you can do something like file.seek(0) to bring the file pointer back to the beginning of the file. I'm guessing that the first read of the file is leaving the file pointer at the end of the file so it looks empty.

Hope this helps, Joe

Answer 2

The most common source of this issue is not adding the attribute enctype="multipart/form-data" to the form tag in your HTML:

<form method="post" enctype="multipart/form-data">

</form>