Django forms, inheritance and order of form fields

From Django 1.9: https://docs.djangoproject.com/en/1.10/ref/forms/api/#notes-on-field-ordering

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Original answer: Django 1.9 will support this by default on the form with field_order:

class MyForm(forms.Form):
    ...
    field_order = ['field_1', 'field_2']
    ...

https://github.com/django/django/commit/28986da4ca167ae257abcaf7caea230eca2bcd80

From Django 1.9+

Django 1.9 adds a new Form attribute, field_order, allowing to order the field regardless their order of declaration in the class.

class MyForm(forms.Form):
    summary = forms.CharField()
    description = forms.CharField(widget=forms.TextArea)
    author = forms.CharField()
    notes = form.CharField()

    field_order = ['author', 'summary']

Missing fields in field_order keep their order in the class and are appended after the ones specified in the list. The example above will produce the fields in this order: ['author', 'summary', 'description', 'notes']

See the documentation: https://docs.djangoproject.com/en/stable/ref/forms/api/#notes-on-field-ordering

Up to Django 1.6

I had this same problem and I found another technique for reordering fields in the Django CookBook:

class EditForm(forms.Form):
    summary = forms.CharField()
    description = forms.CharField(widget=forms.TextArea)


class CreateForm(EditForm):
    name = forms.CharField()

    def __init__(self, *args, **kwargs):
        super(CreateForm, self).__init__(*args, **kwargs)
        self.fields.keyOrder = ['name', 'summary', 'description']

I used the solution posted by Selene but found that it removed all fields which weren't assigned to keyOrder. The form that I'm subclassing has a lot of fields so this didn't work very well for me. I coded up this function to solve the problem using akaihola's answer, but if you want it to work like Selene's all you need to do is set throw_away to True.

def order_fields(form, field_list, throw_away=False):
    """
    Accepts a form and a list of dictionary keys which map to the
    form's fields. After running the form's fields list will begin
    with the fields in field_list. If throw_away is set to true only
    the fields in the field_list will remain in the form.

    example use:
    field_list = ['first_name', 'last_name']
    order_fields(self, field_list)
    """
    if throw_away:
        form.fields.keyOrder = field_list
    else:
        for field in field_list[::-1]:
            form.fields.insert(0, field, form.fields.pop(field))

This is how I'm using it in my own code:

class NestableCommentForm(ExtendedCommentSecurityForm):
    # TODO: Have min and max length be determined through settings.
    comment = forms.CharField(widget=forms.Textarea, max_length=100)
    parent_id = forms.IntegerField(widget=forms.HiddenInput, required=False)

    def __init__(self, *args, **kwargs):
        super(NestableCommentForm, self).__init__(*args, **kwargs)
        order_fields(self, ['comment', 'captcha'])