To set default form values with Django Python, we create the form instance with the default values in the constructor arguments.
Or we can put the default values in the form definition.
For instance, we write
form = JournalForm(initial={'tank': 123})
to create a JournalForm instance with the initial argument set to a dictionary with the initial form values.
In the form definition, we can add a field with its default value by writing
tank = forms.IntegerField(widget=forms.HiddenInput(), initial=123)
to set the initial value using the field constructor with the initial argument set.