1👍
.replace(..)
creates a new string, it does not modify the string. You can thus work with:
def index(request):
change_urls = list(Article.objects.all())
for i in change_urls:
i.url = i.url.replace(' ', '-')
Article.objects.bulk_update(change_urls, fields=('url',))
# …
But if you want to "slugify", please use the slugify(…)
function [Django-doc].
Source:stackexchange.com