serving a favicon in Django's runserver, only in DEBUG

urls.py

# ...

urlpatterns = []

# ...

if settings.DEBUG:
    from django.views.generic.base import RedirectView
    from django.conf.urls.static import static
    from django.contrib.staticfiles.storage import staticfiles_storage
    favicon_url = staticfiles_storage.url('favicon.ico')
    favicon_patterns = [url(r'^favicon\.ico$', RedirectView.as_view(url=favicon_url))]
    # favicon comes first so that any patterns which glob /.+ don't take priority.
    urlpatterns = favicon_patterns + urlpatterns