Multiple-value field for Django forms

The problem

Say we want to use a Django form to validate form input such as the following:

?foo=spam&foo=egg&foo=chips

Django can parse this query-string to generate a list:

>>> request.GET.getlist("foo")
['spam', 'egg', 'chips']

...but it is not yet capable of validating the input using django.forms.

How to use

Say for example, we want to validate a list of email addresses, with a query-string such as the following:

[email protected]&[email protected]

Here are the steps we would take:

1. Install this module (e.g. using pip install django_multivalueformfield)
2. Define a form like the following:

import django.forms as forms

from multivaluefield import MultiValueField

class MultiEmailForm(forms.Form):
    emails = MultiValueField(forms.EmailField(), "email")

3. Pass the QueryDict into the form and validate as per usual:

form = MultiEmailForm(request.GET)
if form.is_valid:
    emails = form.cleaned_data["emails"]
    # do something with emails
else:
    errors = form.errors
    # do something with errors