Default Django checkbox to be true and hidden

I am working with Satchmo and am wondering for the newsletter subscription, how to make it so when people sign up, they are automatically subscribed to the newsletter. I found this line of code in forms.py:

newsletter = forms.BooleanField(label=_('Rece开发者_JAVA技巧ive Daily Deals'),
    widget=forms.CheckboxInput(), required=False)

I am assuming that in the widget there, I can add something to make it automatically be true and hidden.

newsletter = forms.BooleanField(label=_('Receive Daily Deals'),
    widget=forms.HiddenInput(), required=False, initial=True)

You can make checkbox hidden with adding a class to element shown as below:

// css
// .hidden { display: none;}

newsletter = forms.BooleanField(
    label=_('Receive Daily Deals'),
    widget=forms.CheckboxInput(attrs={'class': 'hidden'}), 
    required=False, 
    initial=True
)