• Messages framework

Add this to the config:

INSTALLED_APPS = [
    ...
    'django.contrib.sessions',
    ....
 
MIDDLEWARE = [
    ...
    'django.contrib.sessions.middleware.SessionMiddleware',
    ....

To use them:

# Get a session value by its key (e.g. 'my_car'), raising a KeyError if the key is not present
my_car = request.session['my_car']
# Get a session value, setting a default if it is not present ('mini')
my_car = request.session.get('my_car', 'mini')
# Set a session value
request.session['my_car'] = 'mini'
# Delete a session value 
del request.session['my_car']

• https://docs.djangoproject.com/en/2.1/howto/initial-data/

You will start having a form:

from django import forms
 
class UploadFileForm(forms.Form):
    title = forms.CharField(max_length=50)
    file = forms.FileField()

A view handling this form will receive the file data in request.FILES, which is a dictionary containing a key for each FileField (or ImageField, or other FileField subclass) in the form. So the data from the above form would be accessible as request.FILES['file'].

The form that posted the request has the attribute enctype=“multipart/form-data”. Otherwise, request.FILES will be empty.

For managing this in a view:

def upload_file(request):
    if request.method == 'POST':
        form = UploadFileForm(request.POST, request.FILES)
        if form.is_valid():
            handle_uploaded_file(request.FILES['file'])
            return HttpResponseRedirect('/success/url/')
    else:
        form = UploadFileForm()
    return render(request, 'upload.html', {'form': form})

def handle_uploaded_file(f):
    with open('some/file/name.txt', 'wb+') as destination:
        for chunk in f.chunks():  # Looping over UploadedFile.chunks() instead of using read() ensures that large files don’t overwhelm your system’s memory.
            destination.write(chunk)

If you’re saving a file on a Model with a FileField, using a ModelForm makes this process much easier. The file object will be saved to the location specified by the upload_to argument of the corresponding FileField when calling form.save()

If you are constructing an object manually, you can assign the file object from request.FILES to the file field in the model:

def upload_file(request):
    if request.method == 'POST':
        form = UploadFileForm(request.POST, request.FILES)
        if form.is_valid():
            instance = ModelWithFileField(file_field=request.FILES['file'])
            instance.save()
            return HttpResponseRedirect('/success/url/')
    else:

When a user uploads a file, Django passes off the file data to an upload handler – a small class that handles file data as it gets uploaded. Upload handlers are initially defined in the FILE_UPLOAD_HANDLERS setting.

You can write custom handlers that customize how Django handles files.

By default, if an uploaded file is smaller than 2.5 megabytes, Django will hold the entire contents of the upload in memory. This means that saving the file involves only a read from memory and a write to disk and thus is very fast. However, if an uploaded file is too large, Django will write the uploaded file to a temporary file stored in your system’s temporary directory.