Hi, I'm thinking, maybe instead of:
if obj in queryset: Users should write: if obj in list(queryset): Which I understand is already working? Why does the first line (without list()) should work anyway? And if users want performance, why not write: if queryset.filter(pk=obj.pk).exists(): אורי [email protected] On Tue, Jun 2, 2020 at 11:57 AM Johan Schiff <[email protected]> wrote: > Is there a specific reason Djangos QuerySet does not implement > __contains__? It doesn't seem very complicated to me, but maybe I'm missing > something. > > When checking if an object is in e queryset I always use code lite this: > if queryset.filter(pk=obj.pk).exists(): > > The pythonic way would be: > if obj in queryset: > > The way I understand it this latter version will fetch all objects from > queryset, while the first one is a much leaner db query. > > So, is there a reason QuerySet doesn't have a __contains__ method, or > would it be a good addition? My guess is that a lot of people use the "obj > in queryset" syntax, believing it does "the right thing". > > //Johan > > -- > You received this message because you are subscribed to the Google Groups > "Django developers (Contributions to Django itself)" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/django-developers/88c83b8d-658c-47cc-9162-fcfebebe9c4a%40googlegroups.com > <https://groups.google.com/d/msgid/django-developers/88c83b8d-658c-47cc-9162-fcfebebe9c4a%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "Django developers (Contributions to Django itself)" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/django-developers/CABD5YeE7_ORUfJcnt6f4aB4J0j-%3DyDK_BowEt_fefcaFMGdB1g%40mail.gmail.com.
