Inserting initial data into a SessionWizardView form field either from a URL pattern or post data?

I've pretty much exhausted my resources on this subject, so I must submit a question to the community.

Scenario:

In my urls.py file i have a pattern like:

url(r'^entry_form/(?P<sheet_id>\d+)/', SheetWizard.as_view([Sheet1,Sheet2,Sheet3])),

When a user visits a url like "127.0.0.1/myapp/entry_form/77" I am trying to have Django render Sheet1 but with one of the fields having the value "77" initially entered.

Theroy:

My forms.py file looks similar to:

class Sheet1(forms.ModelForm):
    def __init__(self, *args, **kwargs):
        super(Sheet1, self).__init__(*args, **kwargs)
        #create a helper object
        self.helper = FormHelper(self)
        #dont render the form tags
        self.helper.form_tag = False
        #Make a nice layout
        self.helper.layout = Layout(
             TabHolder(
                             Tab(
                                 'Sheet Information', #Tab name text
                                     PrependedText('sheet_field', 'Django-'), #The field with prepended text
                             )
             )
        #Now set the initial value of the field to sheet_id from url pattern
        self.fields['sheet_field'].initial = str(sheet_id)+'-'+ str( time() ).replace('.','_')
        #??? Not sure where to get sheet_id from???

Notice the last line has a variable named "sheet_id", that should be the value "77" coming from the url pattern entered by the user.

Problem:

So far I am unsure of how to access the value "sheet_id" from the url pattern in my forms.py or views.py files. Due to this being a class based view I can not simply create the keyword "sheet_id=None", aka something like this just doesn't work:

class SheetWizard(SessionWizardView, sheet_id=None):
    #this breaks

I have been able to get some data into views.py using request.GET and a url like "127.0.0.1/myapp/entry_form/?sheet_id=77" but I have no idea how to pipe that into the first form of the SessionWizardView user session.

It would be greatly appreciated if someone could help me out. And thanks for all your kind wisdom!

Use the wizard's dispatch method:

def dispatch(self, request, *args, **kwargs):
    self.sheet_id = kwargs.get('sheet_id', None)
    return super(SheetWizard, self).dispatch(request, *args, **kwargs)

Then use self.sheet_id within get_form_initial method to populate initial value for your form.